taxonID	type	description	language	source
5C0DC869AD47D64FE7B1F97907A6FE33.taxon	description	Figs. 1, 2 A, B, 3 A Lectotype. BMNH 1946.1. 6.58, obtained by A. S. Meek in Trobriand Islands, Milne Bay Province, Papua New Guinea, designated herein. Paralectotypes. BMNH 1946.1. 6.57, 1946.1.6.59 – 61, same data as lectotype. Additional Material. Papua New Guinea: Central Province: Edevu, 9.2130 ° S, 147.3097 ° E (NHM 2013.275); Milne Bay Province: Alotau, 10.3067 ° S, 150.4381 ° E, 5 m a. s. l. (BPBM 20817); Opea Island, 10.6034 ° S, 150.0113 ° E, 0 – 1 m a. s. l. (UMMZ 245411). Photographs only: Papua New Guinea: Milne Bay Province: Menapi, Cape Vogel, 9.767 ° S, 149.917 ° E (AMNH 73940); Iamalele # 1, 9.489 ° S, 150.543 ° E, Fergusson Island (AMNH 76642); Morobe Province: Garaina, 7.88 ° S, 147.14 ° E (AMNH 95613, 107175).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD47D64FE7B1F97907A6FE33.taxon	diagnosis	Diagnosis. A moderately sized species of Dendrelaphis (adult SVL up to 856 mm, tail up to 386 mm; TL / SVL = 0.30 – 0.36); eye approximately equal in diameter to eye-naris distance (EY / EN = 0.92 – 1.11, mean = 1.01); ventrals 189 in sole male, 182 – 190 in seven females; subcaudals 120 in sole male, 125 – 133 in five females; hemipenis without a terminal awn, ornamented proximally with a few whorls of large spines; black bars absent from neck; dark postocular stripe present; venter uniformly tan or yellow, unspotted; dorsum tan; anterior vertebral scales paler than remainder of dorsum, imparting the appearance of a pale anterior vertebral stripe; head tan, lacking dark speckles; supralabials cream with brown or black markings dorsally; chin yellow, often with a few gray specks. Comparisons with other species. Dendrelaphis papuensis differs from D. lineolatus and D. striolatus in lacking black bars on the neck and in having fewer subcaudals (120 – 133 vs. 144 – 151 in D. lineolatus and 133 – 147 in D. striolatus); from D. lorentzii in lacking dark speckling on the head, having more ventrals (182 – 190 vs. 156 – 181 in D. lorentzii), and in having an eye subequal in size to the EN distance (vs. eye much smaller than EN distance in D. lorentzii); from D. keiensis, D. macrops, and D. punctulatus in having a dark postocular stripe; from D. gastrostictus in lacking dense black spotting on the venter; and from D. calligastra in having fewer subcaudals (120 – 133 vs. 134 – 156 in D. calligastra), no terminal awn on hemipenis (vs. present in D. calligastra), and hemipenis with a few whorls of large spines proximally (vs. with numerous tiny spines proximally in D. calligastra). The pale anterior vertebral stripe and the large spines on the base of the hemipenes distinguish D. papuensis from all other Melanesian members of the genus.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD47D64FE7B1F97907A6FE33.taxon	description	Redescription of the lectotype. Adult female. Dorsal scale rows 15 - 13 - 11, reduction to 13 rows occurs at the level of Ventral 13 and to 11 rows at Ventral 115; all scales smooth. Vertebral scales hexagonal; paravertebral scales elongated, semi-hexagonal; remainder narrowly rhomboidal and oblique to body axis. Rostral slightly wider (2.9 mm) than high (2.4 mm); internasals, frontal, supraoculars, and parietals longer than wide; prefrontals wider than long; lateral extension of parietal contacts upper postocular; nasals divided by large nares, with short dorsal and ventral sutures extending from top and bottom of naris to internasal and first supralabial, respectively; one loreal on each side, longer than high; preocular single, higher than long; postoculars two, upper more than twice as large as lower; anterior temporals two, upper smaller than lower (Fig. 1). Supralabials 8, 4 th and 5 th below eye; infralabials ten, five contact anterior genials. Posterior genials in contact with infralabials 5 (point contact only) and 6, separated along their posterior half by pair of intergenials; single lateral gular separates posterior genials from infralabial 7. Many small tubercles present on all head shields except frontal. Vertebral scales hexagonal; remaining dorsal scales oblique. Dorsal scales on tail in ten rows at level of cloaca, four rows at midtail, and two rows near tip. Ventrals 187; cloacal scale divided; subcaudals 123 +, last two or three subcaudals missing; ventrals and subcaudals each with a ventrolateral ridge. Total length 1029 mm; snout-vent length 724 mm; tail length 305 mm, small portion of tip missing. Dorsal ground color in preservative pale brown, heavily dusted with black on lateral and dorsolateral scale rows beginning around ventral 5 and gradually decreasing posteriorly into sparse flecks; this black field extending approximately 25 % of body. Vertebral scale row lighter than surrounding scales anteriorly, margined in black, forming pale stripe to approximately ventral 43; vertebral scales with elliptical white blotch on each anterolateral margin, these decreasing in size posteriorly and disappearing at approximately midbody. Similarly, anterior of each lateral scale with an elliptical white blotch on ventral margin, these too decreasing in size posteriorly and disappearing at midbody. Black postocular stripe extends from eye to end at black lateral field that begins at ventral 6. Labials, chin, and throat pale yellow. All supralabials except the first margined above with black. Infralabials and genials with few gray flecks. Yellow throat changes posteriorly to tan shortly beyond neck, which continues through tail. Each ventral with narrow brown streak on ventrolateral ridge of each scale; these marks absent on subcaudals, the ridges of which are white. Iris black. Variation. The paralectotypes show little meristic variation (Table 1) and are virtually identical to the lectotype in coloration. The sole neonate (BMNH 1946.1.6.59) has a slightly shorter tail (tail / SVL = 0.28) than do the adults (tail / SVL = 0.30 – 0.36). Scales missing the corneous epidermis are pale gray instead of tan. The venter is paler yellow in the smallest specimen (BMNH 1946.1.6.59), quickly changing posteriorly to cream and then tan. For the specimen from Opea Island (Fig. 2 A), just off the southernmost tip of New Guinea (UMMZ 245411) the black anterolateral color field and the black postocular stripe are not as densely developed as in the type series from the Trobriand Islands. The iris has a narrow margin of silver around the pupil. The venter is pale gray irregularly marked with small flecks or streaks of darker gray or black (Fig. 2 B). Linear streaks on the ventrolateral ridges are black instead of brown. Overall, this specimen is grayer than the type series, which may reflect either geographic variation in color or the longer period of time in preservative of the type series. The neonate has narrow black preocular, postocular, and neck stripes; whereas adults maintain a wide black postocular stripe, which is beginning to be broken up with brown in the largest specimen (BMNH 1946.1.6.57) and in the specimen from Opea Island. Color in life. Judging from a photo in life, this species looks much like it does in preservative, being tan dorsally with a paler tan vertebral stripe and wider dorsolateral stripe that is black anteriorly and soon changes posteriorly to become brown with each scale having a central white area (Fig. 3 A). It has a narrow black postocular stripe, and the labials and lower sides are white anteriorly.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD47D64FE7B1F97907A6FE33.taxon	etymology	Etymology. The species name denotes that this species comes from Papua. Range. This species was conservatively interpreted by van Rooijen et al. (2015) to be restricted to the Trobriand Islands, but I have found it to also occur in southeastern mainland New Guinea (Fig. 4), as reported by McDowell (1984), who stated its distribution to be throughout the Papuan Peninsula as well as in Western Province. That this species is not endemic to the Trobriand Islands is unsurprising considering that those islands were entirely continuous with New Guinea during the last glaciation. Based on current evidence — including photographs of specimens seen by me — this species seems to occur across most or all of the Papuan Peninsula of New Guinea with certainty, but McDowell’s report of this species from farther west — apparently based only on reports from Fred Parker but not direct examination of specimens — requires verification.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD47D64FE7B1F97907A6FE33.taxon	biology_ecology	Ecology. Like many Papuan Dendrelaphis, this species seems to adapt well to human-modified areas so long as trees and shrubs remain. The Trobriand Islands are largely converted to gardens, my specimen from Alotau came from a well-landscaped lodge, and the specimen from Opea Island came from an offshore islet with native strand vegetation.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD47D64FE7B1F97907A6FE33.taxon	discussion	Remarks. Boulenger (1895) made clear that he based his description of the species on “ several specimens ”, these several apparently being the five BMNH specimens referred to as syntypes by van Rooijen et al. (2015) and The Reptile Database (Uetz et al. 2024). However, although he gave ranges of variation for numbers of ventrals and subcaudals, Boulenger (1895) provided length information for only one specimen, giving values of total length of 1050 mm and tail length of 310 mm, leaving the SVL to be 740 mm by subtraction. These values do not correspond exactly to my measurements of those specimens, but they are closest to that I have chosen to be the lectotype (BMNH 1946.1.6.58), for which I get values of 1029, 305, and 724 mm, respectively. These values are consistent with some shrinkage / distortion of the specimen in the intervening 130 years; other specimens are either too large or much too small to have been the specimen for which Boulenger provided measurements (Table 1). Boulenger (1895) did not provide information on the sex of his specimens, so that could not be used in verifying my choice of lectotype. Identification of this species in the literature has been problematic. The pale anterior vertebral stripe that I find diagnostic for the species was noted in the original description by Boulenger (1895), but he made no special note of its importance. Presence of this feature was repeated by de Rooij (1917) and O’Shea (1996), though neither noted its diagnostic importance. Furthermore, this character was not mentioned by van Rooijen et al. (2015), whose diagnoses among many of the Melanesian Dendrelaphis otherwise relied on several color-pattern features. McDowell (1984) also did not emphasize this attribute because his study was focused on the snakes of the Huon Peninsula, on which D. papuensis is lacking. Despite the fact that his explication of the geographic distribution of this species seems largely to have relied on examination of hemipenes (with the exception of snakes from Western Province, as noted above), information on the presence or absence of the pale vertebral stripe on specimens from mainland New Guinea is lacking, although I have verified its presence on several specimens from throughout the Papuan Peninsula (Fig. 4). McDowell (1984) mentioned that this color-pattern feature was seen in many, but not all, specimens of this species, but inasmuch as he included in his concept of that species three of the species described below — two of which are unstriped — does not allow one to infer whether other specimens he examined from mainland New Guinea also lacked the vertebral stripe. Consequently, as noted above, additional examination of specimens from New Guinea must be had to clarify whether this feature truly varies in D. papuensis, what the exact geographic distribution of that species is on New Guinea, and whether additional species may be involved in samples from that island. Thus, the distribution for this species provided by Tallowin et al. (2016) for the IUCN Red List must be viewed as provisional and requiring verification. What is untenable — and clearly refuted by the data presented here — is that D. papuensis is endemic to the low-elevation Trobriand Islands, which were broadly connected to the New Guinea mainland during the last glaciation.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	description	Figs. 3 B, 5, 6	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	materials_examined	Holotype. BPBM 39678 (field number FK 14930), adult female, obtained from villagers by F. Kraus, Kulumadau, 9.08 ° S, 152.72 ° E, 100 m a. s. l. Woodlark Island, Milne Bay Province, Papua New Guinea. Paratypes (n = 8). Papua New Guinea: Milne Bay Province: Woodlark Island: Kulumadau (AMNH 76615 – 18, 76625); Guasopa, 9.16 ° S, 152.98 ° E, 5 m a. s. l. (BPBM 17891 – 92); vicinity of Talpos River, 9.16 ° S, 152.78 ° E, 100 m a. s. l. (BPBM 17893).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	diagnosis	Diagnosis. A moderately sized species of Dendrelaphis (SVL up to 728 mm, tail up to 318 mm; TL / SVL = 0.32 – 0.33 in five adults with complete tails); eye approximately equal in diameter to eye-naris distance (EY / EN = 0.98 – 1.22, mean = 1.13); ventrals 179 – 185 in five males, 184 – 187 in four females; subcaudals 131 – 135 in two males, 132 – 145 in three females; hemipenis without a terminal awn, ornamented proximally with a few whorls of large spines; black bars absent from neck; body brown dorsally and ventrally in juveniles changing to dark gray or black in adults; before turning entirely black, paler anterior vertebral stripe present that is margined in black; supralabials white heavily stained with black throughout; infralabials and chin white heavily suffused with black; anteriormost 2 – 6 ventrals mostly white, stained with some black; subcaudals black centrally, ventrolateral ridges of subcaudals white. Comparisons with other species. The pale anterior vertebral stripe and the large basal spines on the hemipenes distinguish Dendrelaphis roseni sp. nov. from all other Melanesian members of the genus except D. papuensis. From that species, D. roseni sp. nov. differs in its larger eye (EY / EN = 0.98 – 1.22, mean = 1.13 vs. 0.92 – 1.11, mean = 1.01 in D. papuensis); dorsum and venter gray in juveniles changing to black in adults (vs. tan in D. papuensis), thereby encroaching on and reducing contrast with the pale vertebral stripe (vs. stripe distinct throughout life in D. papuensis); absence of a black postocular stripe (vs. present in D. papuensis); labials and chin white stained / suffused with black (vs. cream or yellow in D. papuensis); and subcaudals black with white ventrolateral ridges (vs. tan in D. papuensis). The ontogenetic melanization of animals such that most adults are dark gray or black distinguishes D. roseni from all other Melanesian species of the genus, all of which are brown or green above and white, yellow or brown below. Dendrelaphis roseni sp. nov. further differs from D. lineolatus and D. striolatus in lacking black bars on the neck; from D. lorentzii in lacking dark speckling on the head, in having more ventrals (179 – 187 vs. 156 – 181 in D. lorentzii), and having an eye subequal to or larger in size to the EN distance (vs. eye much smaller than EN distance in D. lorentzii); from D. gastrostictus and D. calligastra in lacking any indication of a dark postocular stripe in most adults, and further from D. gastrostictus in lacking dense black spotting on the venter; from D. keiensis in having fewer ventrals (179 – 187 vs. 211 – 213 in D. keiensis) and a longer tail (TL / SVL = 0.32 – 0.33 vs. 0.29 – 0.30 in D. keiensis), and from D. calligastra, D. macrops and D. punctulatus in lacking a terminal awn on the hemipenis (vs. present in those species), and the hemipenis having a few whorls of large spines proximally (vs. with numerous tiny spines proximally in those species).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	description	Description of the holotype. Adult female. Dorsal scale rows 15 - 13 - 11, reduction to 13 rows occurs at the level of Ventral 10 and to 11 rows at Ventral 112; all scales smooth. Vertebral scales hexagonal; paravertebral scales elongated, semi-hexagonal; remainder narrowly rhomboidal and oblique to body axis. Rostral half again as wide as high; internasals, frontal, supraoculars, and parietals longer than wide; prefrontals wider than long; lateral extension of parietal contacts upper postocular; nasals divided by large nares, with short dorsal and ventral sutures extending from anterior of naris to internasal and first supralabial, respectively; two loreals on each side, all longer than high; preocular single, higher than long; postoculars two, upper larger; anterior temporals two, upper shorter than lower on right but reverse on left; posterior temporals 4 (R) and 3 (L) (Fig. 5). Supralabials 8, 5 th and 6 th (R) or 4 th and 5 th (L) below eye; infralabials 9 (right) and 10 (left), five contact anterior genials. Posterior genials in contact with infralabials 5 and 6, separated along their posterior half by pair of intergenials; single lateral gular separates posterior genials from infralabial 7. Many small tubercles present in the rostral, nasals, internasals, prefrontals, loreals, preoculars, postoculars, temporals, supralabials, mental, infralabials, and genials; absent from the frontal, supraoculars, and parietals. Vertebral scales hexagonal; remaining dorsal scales oblique. Dorsal scales on tail in six rows at level of cloaca, four rows at midtail, and two rows near tip. Ventrals 184; cloacal scale divided; subcaudals 95 +; ventrals and subcaudals each with a ventrolateral ridge. Total length 999 mm; snout-vent length 728 mm; tail length 271 mm, tip missing; mass 83.3 g in life. Dorsal ground color in preservative largely black except scales of vertebral row with white spot in each (Fig. 6 A), and first and second rows white marked with black to ~ ventral 70, with amount of white decreasing and amount of black increasing posteriorly (Fig. 6 B); white markings also intrude into the black on scale rows 3 – 6 from ventral 32 to ~ ventral 70. Head black except supralabials, mental, and infralabials white heavily marked with black; genials uniformly white. Throat and anterior ventrals white marked with black, gradually darkening posteriorly, becoming largely black by ventral 75. Ventrolateral ridges of each ventral and subcaudal with white longitudinal line, faintest just anterior to cloaca. Iris black. Variation. One unusual feature of this species is that the number of loreals varies, usually being one, as is seen in all other Dendrelaphis I have examined. But the holotype as well as BPBM 17891 have two loreals on each side, one above the other; and BPBM 17892 has two loreals on the right side and one on the left. Supralabials vary from 8 – 9 (Table 2), with the fourth and fifth usually entering the eye, though the fifth and sixth do on one side of three specimens. Infralabials are usually nine or ten but are 11 on the right side of BPBM 17893. There is no evidence of sexual dimorphism in subcaudal counts (but only two males and three females had complete tails), though ventrals may be slightly greater in females (184 – 187) than males (179 – 185) (Table 2). The smallest specimen (BPBM 17893, SVL = 230 mm) is light brown above and below and has a vague suggestion of the beginning of a dark postocular stripe, with the dorsal margins of the lower temporals being dusted with darker brown than the adjacent scales; the supralabials of this specimen are yellow with a few brown flecks. Larger specimens may be brown dorsally with each scale margined in black (e. g., BPBM 17891 – 92, Fig. 6 C, E) but are usually dark gray (AMNH 76618) or black (all others). Degree of melanization seems to vary individually, and this is most evident on the venter, which may be uniformly black (but with a white chin / throat), as seen in the holotype (SVL = 728 mm, Fig. 6 B) and in AMNH 76616 (SVL = 672 mm), but can also be gray mottled with black or with the posterior margin of each scale black (e. g., AMNH 76615, 76617 – 18, 76625, SVL = 509, 675, 597, and 658 mm, respectively). Two BPBM specimens are more anomalous in this regard: BPBM 17891 (SVL = 534 mm, Fig. 6 D) is yellow cream with a few short black streaks, and BPBM 17892 (SVL = 675 mm, Fig. 6 F) is pale yellow with a blue cast and is mottled with black posteriorly. These specimens are also among the few with a dark postocular stripe. The pale anterior vertebral stripe is evident in all specimens but is reduced by encroaching melanization to a series of vertebral spots in AMNH 76616 – 17 and 76625. AMNH 76618 is gray above with a darker postocular stripe evident. Color in life. The holotype (Fig. 3 B) was recorded as “ Jet black above except that anterior dorsal row 1 yellow and black, darkening to tan and black and then solid black posteriorly. A brown spot present on each vertebral scale anteriorly but turning to solid black posteriorly at ~ midbody. Chin white marked with black; ventrals yellow marked with black anteriorly, changing to tan and black and then solid black posteriorly except that the ventral [ventrolateral] keels and subcaudal [ventrolateral] keels each have a cream longitudinal streak, giving to the ventral side a series of cream dashes on each side. Iris white above the pupil, otherwise black. Tongue black. ”	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	etymology	Etymology. This species is a genitive honorific for my late friend, snake ecologist and conservationist Philip Clark Rosen. Range. This species is restricted to Woodlark Island (Fig. 4).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	biology_ecology	Ecology. I have no specifics on the ecology of this species, though most specimens were taken from the villages of Kulumadau (holotype, AMNH series) or Guasopa (BPBM 17891 – 92); only BPBM 17893 came from rainforest. However, prior to human occupation, Woodlark was entirely forested, so this species would appear to thrive in either rainforest or villages and gardens established by humans.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD4DD64AE7B1FA0301FCFD43.taxon	discussion	Remarks. Melanization in this species clearly proceeds ontogenetically from posterior to anterior, but there is individual variation in its rate of development. The least melanized specimens still have black developing in the center of the subcaudals and on the margins of the posterior ventrals; specimens with more melanization have black mottling on the rear of the venter, and the most melanized have the venter entirely black posteriorly and either black or dark gray anteriorly. The adults with the least melanized patterns (BPBM 17891 – 92) came from the far east of Woodlark, whereas the darker specimens came from 30 km west of there. Possibly these color differences reflect geographic variation on the island, but sample sizes are too small to infer that with any confidence.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	description	Figs. 2 C, D, 7, 8 A	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	materials_examined	Holotype. BPBM 20838 (field number FK 9812), adult male, obtained from local collectors by F. Kraus, Vutha, on far side of ridge due west of Camp 1, 11.4918 ° S, 153.3846 ° E, ~ 80 m a. s. l., Sudest Island, Milne Bay Province, Papua New Guinea. Paratypes (n = 5). Papua New Guinea: Milne Bay Province: Sudest Island: Araeda, 11.4362 ° S, 153.4301 ° E, 1 – 20 m a. s. l. (BPBM 20837); Rambuso, 0 – 100 m a. s. l. (AMNH 76648); west slope Mt. Rio, 250 – 350 m a. s. l. (AMNH 76655 – 57).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	diagnosis	Diagnosis. A large species of Dendrelaphis (adult SVL up to 960 mm, tail up to 460 mm; TL / SVL = 0.31 – 0.33); eye approximately equal in diameter to eye-naris distance (EY / EN = 0.92 – 1.00, mean = 0.95); ventrals 178 – 188 in four males, 187 in two females; subcaudals 134 – 139 in four males, 140 – 142 in two females; hemipenis without a terminal awn, ornamented proximally with a few whorls of large spines; dorsum and most of venter uniformly black; supralabials white on lower third to half, black dorsally; infralabials and chin uniformly white or white with few black flecks. Comparisons with other species. The complete melanization of adults distinguishes Dendrelaphis anthracina sp. nov. from all other Melanesian members of the genus. It further differs from all other species except D. papuensis and D. roseni sp. nov. in having a region of large spines around the proximal third of the hemipenis. From D. papuensis, D. anthracina sp. nov. further differs in its slightly greater number of subcaudals (134 – 142 vs. 120 – 133 in D. papuensis); smaller eye (EY / EN = 0.92 – 1.00, mean = 0.95 vs. 0.92 – 1.11, mean = 1.01 in D. papuensis); narrower snout (EN / SWnares = 0.79 – 0.95, mean = 0.84 vs. 0.72 – 0.87, mean = 0.79, respectively, in D. papuensis); and wider frontal scale (FW / SWnares = 0.76 – 0.85, mean = 0.81 versus 0.57 – 0.87, mean = 0.76 in D. papuensis). From D. roseni sp. nov., D. anthracina sp. nov. further differs in its smaller eye (EY / EN = 0.92 – 1.00, mean = 0.95 vs. 0.98 – 1.22, mean = 1.13 in D. roseni sp. nov.), uniformly black dorsum (vs. first scale row yellow or tan and vertebral scale row with series of brown spots anteriorly in D. roseni sp. nov.) and venter (vs. black posteriorly and yellow or tan anteriorly in living D. roseni sp. nov.), chin and labials glossy white (vs. matte white heavily marked with gray in D. roseni), and supralabials white on the lower third to half and black on upper half to two-thirds, with a sharp demarcation between the two (vs. supralabials white and heavily dusted or stained with black throughout in D. roseni sp. nov.).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	description	Description of the holotype. Adult male, hemipenes everted. Dorsal scale rows 14 - 13 - 11, reduction to 13 rows at ventral 9 and to 11 rows at ventral 100; all scales smooth. Vertebral scales hexagonal, remainder narrowly rhomboidal and oblique to body axis, paravertebral row wider. Rostral half again as wide as high; internasals, frontal, supraoculars, and parietals longer than wide; prefrontals wider than long; lateral extension of parietal contacts upper postocular; nasals divided by large nares, with short dorsal suture extending from anterior of naris to internasal on both sides, short ventral suture extending from anterior of naris to first supralabial on both sides; loreal single, elongate; preocular single, higher than long; postoculars two, upper larger; anterior temporals two, upper larger than lower on right, reversed on left; posterior temporals 3 (R) and 6 (L) (Fig. 7). Supralabials 9, 5 th and 6 th below eye; infralabials 10, 5 (R) and 6 (L) contact anterior genials. Posterior genials in contact with infralabials 5 and 6 (R) and 6 and 7 (L), separated along their posterior half by pair of intergenials; single lateral gular separates posterior genials from infralabial 7 (R) or 8 (L). Many small tubercles present in the rostral, nasals, internasals, prefrontals, loreals, preoculars, frontal, supraoculars, parietals, mental, infralabials, and genials; shallow pits present on loreals, preoculars, postoculars, temporals, supralabials, and lateral edge of parietals. Vertebral scales hexagonal; remaining dorsal scales oblique. Dorsal scales on tail in nine rows at level of cloaca, six rows at second ventral, four rows at midtail, and two rows near tip. Ventrals 182; cloacal scale divided; subcaudals 136; ventrals and subcaudals each with a ventrolateral ridge. Total length 1420 mm; snout-vent length 960 mm; tail length 460 mm, tail complete; mass 215 g in life. Hemipenis unilobed, widest at one-third length of organ from base, narrower distal to that. Base of organ nude and with small pleats, followed distally by a short zone of small spicules, this followed distally by a zone of large spines starting approximately 25 – 33 % along organ, these spines smaller distally than proximally; terminal half of hemipenis densely covered with small spicules (Fig. 8 A). Sulcus spermaticus narrow, unforked, arising from junction of base with tail, continuing more or less straight to terminus or organ, not diverging to left or right. Left side of sulcus spermaticus with large nude semi-circular patch at junction where large spines meet the terminal spicules, this nude field margined all around by a raised spiculose lip or shelf identical to that bordering the sulcus spermaticus. Hemipenis crowned with a small inverted, spiculose pocket. Dorsal ground color in preservative uniform black (Fig. 2 C); supralabials black dorsally, white ventrally; infralabials and genials white, narrowly margined with black on infralabials 3, 5, and 6 (R) and infralabials 1, 4, and 5 (L) (Fig. 2 D). First three ventrals white marked with black, next four ventrals black marked with white, remainder black like dorsum, slightly paler than dorsum on tail; ventrolateral ridges narrowly corneous brown. Iris black. Variation. Available specimens vary from 470 – 960 mm SVL and 699 – 1420 mm total length, and mensural ratios of potential interest fall within very tight ranges (Table 3). Numbers of ventrals and subcaudals also fall within narrow ranges (Table 3), and there is no obvious difference in these counts between the sexes. Number of loreals on each side is uniformly one, though temporals vary from 5 – 8, with most snakes having six or seven. Supralabials vary from 8 – 10 on each side; typically supralabials 5 and 6 subtend the eye, but sometimes supralabials 4 and 5 touch the eye instead. Infralabials are uniformly ten on each side. Everted hemipenes available only for the holotype. The dorsum is uniformly black in all specimens except BPBM 20837, which is dark brown; there is never a trace of an anterior vertebral stripe nor a postocular stripe. The venter is uniformly black with a glossy white chin in all specimens, except BPBM 20837 (SVL = 896 mm), which is dark brown instead of black. AMNH 76656 has white markings on the first 14 subcaudals, and AMNH 76657 has them on the first 25 ventrals. These are the two smallest specimens (SVL = 631 mm and 470 mm, respectively), suggesting that there may be some degree of posterior-to-anterior ventral melanization during ontogeny. The infralabials and gulars are uniformly white in most specimens, but AMNH 76656 has a few tiny black flecks on some of these scales, and AMNH 76648 (SVL = 942 mm) has some small black spots posterior to the gulars. In all specimens, the lower third to half of the supralabials is uniformly white and the upper half to two-thirds solid black, with a sharp demarcation between the two.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	etymology	Etymology. The species name is a feminine Latin adjective meaning “ coal black ” in recognition of its shiny black coloration. Range. As currently known, this species is restricted to Sudest Island (Fig. 4) but may eventually be found on smaller islands of the Calvados Chain, which are contained within the fringing reef that demarcated the larger Sudest Island during glacial periods.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	biology_ecology	Ecology. We saw several uncaptured individuals active during daytime in primary or disturbed secondary rainforest, especially in the vicinity of streams, but like other Dendrelaphis, animals are difficult to capture. Specimens were taken both from the coastal villages of Araeda (BPBM 20837) and Rambuso (AMNH 76648) as well as from inland rainforest (AMNH 76655 – 57, BPBM 20838). However, prior to human occupation, Sudest was entirely forested, so this species would appear to have a wide ecological tolerance ranging from rainforest to villages and gardens established by humans. When found, BPBM 20837 was located on the ground adjacent to a stream and wrapped around a goshawk that had apparently attacked it and had been rendered immobile by the snake’s enveloping defensive reaction.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD48D656E7B1FD0D05E8FD43.taxon	discussion	Remarks. Contrary to the description of the hemipenes provide by McDowell (1984) on the basis of examining dissected, uneverted organs, I do not find the terminal half of the organ to be calyculate, nor do I find a transverse ridge separating the large basal spines from the distal field of small spicules. Instead, I find a small, semi-circular nude patch on the left side of the sulcus spermaticus, with a raised ridge flared out to cover the margin of this patch, but it does not form a continuous ridge around the organ by any means (Fig. 8 A). I presume this difference in our observations reflects the difficulty of determining hemipenial morphology accurately when in the uneverted position.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	description	Figs. 2 E, F, 3 C, 8 B, 9	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	materials_examined	Holotype. BPBM 20845 (field number FK 10302), adult male, F. Kraus, along Rupu R., 11.3354 ° S, 154.2247 ° E, 280 m a. s. l., Rossel Island, Milne Bay Province, Papua New Guinea. Paratypes (n = 20). Papua New Guinea: Milne Bay Province: Rossel Island: same locality as holotype (BPBM 20849); Gobubob, ~ 1 km NNW Camp 3, 11.3354 ° S, 154.2223 ° E, 275 m a. s. l. (BPBM 20844, 20851); 11.3327 ° S, 154.2248 ° E, 156 m a. s. l. (BPBM 20846 – 48); above Mission station at Jinjo, 11.3179 ° S, 154.2353 ° E (BPBM 20850); Cheme, 11.3231 ° S, 154.2428 ° E, 5 m a. s. l. (BPBM 20852); Jinjo, 11.315 ° S, 154.236 ° E, 0 – 100 m a. s. l. (AMNH 76661 – 66); Abaleti, 11.394 ° S, 154.198 ° E 0 – 50 m a. s. l. (AMNH 76672 – 76); no specific data (AMNH 89362).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	diagnosis	Diagnosis. A large species of Dendrelaphis (adult SVL up to 1055 mm, tail up to 440 mm; TL / SVL = 0.26 – 0.33); eye approximately equal in diameter to eye-naris distance (EY / EN = 0.93 – 1.22, mean = 1.00); ventrals 187 – 191 in seven males, 181 – 202 in 12 females (two juveniles are too small to sex); subcaudals 143 – 147 in four males with complete tails, 127 – 142 in nine females with complete tails; hemipenis without a terminal awn, ornamented proximally with a few whorls of large spines; dorsum in life bluish bronze, each scale margined in black, without a vertebral stripe; venter bluish gray or bluish yellow; labials and chin yellow suffused or dusted with bluish gray or brown; a black postocular stripe widens and extends down the anterior neck to separate the dark dorsum from the paler venter. Comparisons with other species. The large spines around the proximal end of the hemipenis distinguish Dendrelaphis melanarkys sp. nov. from all other Melanesian members of the genus except D. papuensis, D. roseni sp. nov., and D. anthracina sp. nov. It differs from D. papuensis and D. roseni sp. nov. in lacking the anterior vertebral stripe of those species and in having the dorsal scales each margined in black; it further lacks the uniformly tan dorsum of D. papuensis and the dorsal and ventral melanization seen in D. roseni sp. nov. Dendrelaphis melanarkys sp. nov. differs from D. anthracina sp. nov. in its bluish-bronze dorsum, bluish-gray or bluish-yellow venter, and presence of a black postocular stripe that widens on the anterior neck; D. anthracina sp. nov. is uniformly black above and below and lacks a postocular stripe. D. melanarkys sp. nov. further differs from these species in having more ventrals (187 – 191, mean = 189.7 in seven males, 181 – 202, mean = 195.2 in 11 female D. melanarkys sp. nov. vs. 179 – 185 in five male, mean = 182.4 and 184 – 187, mean = 185.0 in four female D. roseni sp. nov.; 182 – 190, mean = 185.2 in six female D. papuensis, and 178 – 188, mean = 182 in four male and 187 in two female D. anthracina sp. nov.).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	description	Description of the holotype. Adult male, hemipenes everted. Dorsal scale rows 15 - 13 - 11, reduced to 13 rows at ventral 16, reduced to 11 rows at ventral 108; all scales smooth. Vertebral scales hexagonal, remainder narrowly rhomboidal and oblique to body axis, paravertebral row wider. Rostral half again as wide as high; internasals, frontal, supraoculars, and parietals longer than wide; prefrontals wider than long; lateral extension of parietal contacts upper postocular; nasals divided by large nares, with short dorsal suture extending from posterior of naris to internasal on both sides, short ventral suture extending from anterior of naris to first supralabial on both sides; loreal single, elongate; preocular single, higher than long; postoculars two, upper larger on right, lower larger on left; anterior temporals one on right, two on left, upper larger than lower; posterior temporals 5 (R) and 6 (L) (Fig. 9). Supralabials 8, 4 th and 5 th below eye; infralabials 10, 5 contact anterior genials. Posterior genials in contact with infralabials 5 and 6, separated along their posterior half by pair of intergenials; single lateral gular separates posterior genials from infralabial 7. Many small tubercles present in the rostral, nasals, internasals, prefrontals, loreals, preoculars, supralabials, mental, infralabials, and genials; shallow pits present on loreals, preoculars, postoculars, temporals, supralabials 2 – 5, and postoculars. Vertebral scales hexagonal; remaining dorsal scales oblique. Dorsal scales on tail in six rows at second ventral, four rows at midtail, and two rows near tip. Ventrals 191; cloacal scale divided; subcaudals 147; ventrals and subcaudals each with a ventrolateral ridge. Total length 1047 mm; snout-vent length 705 mm; tail length 342 mm, tail complete; mass 51.8 g in life. Hemipenis unilobed, widest at one-third length of organ from base, narrower distal to that. Base of organ nude and with small pleats, followed distally by a short zone of small spicules, this followed distally by a zone of large spines starting approximately 25 – 33 % along organ, these spines smaller distally than proximally; terminal half of hemipenis densely covered with small spicules (Fig. 8 B). Sulcus spermaticus narrow, unforked, arising from junction of base with tail, continuing more or less straight to terminus of organ, not diverging to left or right. Left side of sulcus spermaticus with large nude semi-circular patch at junction where large spines meet the terminal spicules, this nude field margined all around by a raised spiculose lip or shelf identical to that bordering the sulcus spermaticus. Hemipenis crowned with a small inverted, spiculose pocket. Dorsal ground color in preservative bluish gray with vague cream mottling in each scale; dorsal scales margined in black dorsally and posteriorly, giving appearance of diagonal narrow black lines running anteroventrally from vertebral scale row. Vertebral scales with white margins on the two anterolateral margins, black on the other margins. Top and sides of head medium brown; supralabials and infralabials yellow with sparse blue-gray dusting; wide black postocular stripe runs behind eye to corner of jaw, expanding in width to include three lateral scale rows to ventral 10, after which becoming broken and narrower, finally ending between ventrals 31 – 39. Chin, throat, and anterior venter yellow cream changing to blue gray infused with pale yellow cream posteriorly. Under tail paler blue gray than adjacent dorsum. Each ventral with narrow black streak on posterior half to two-thirds of each ventrolateral ridge. Iris black with some silver dorsally. Variation. Available adult and subadult specimens vary from 431 – 1055 mm SVL and 605 – 1494 mm total length; the three juveniles (BPBM 20844, 20849, AMNH 89362) have SVL = 317 mm, 348 mm, and 286 mm and total lengths of 455 mm, 498 mm, and 410 mm, respectively. Mensural ratios of potential interest differ little between the sexes, though there is a suggestion that males may possibly have slightly larger eyes (Table 4). Females appear to have slightly more ventrals and slightly fewer subcaudals than males, though the difference is not great (Table 4). Hemipenes on six of the paratypes do not differ from those seen in the holotype. In all specimens there is no trace of a vertebral stripe, with the vertebral scale row the same color as the remaining dorsal scales. The juveniles have a bold anterolateral row of black blotches on each side behind the postocular stripe that continues down the neck; in adults these disappear or become obscure with additional melanization of the intervening areas in the largest adults, though they are still evident in smaller adults. In juveniles, the black margining to the dorsal scales is evident anteriorly but disappears posteriorly; all recently collected adults have an obvious network of black margining to the dorsal scales across the entire dorsal surface (Fig. 2 E), though in half of the sample of AMNH specimens, which were collected in 1956, this black margining is no longer evident. The black margining is strongest on the anterior and posterior margins of each scale, imparting an overall appearance of narrow, diagonal black stripes across the dorsum (Fig. 3 C). The black postocular stripe is evident in all recently collected specimens, is clearly evident in five of the AMNH specimens from 1956, but is not clearly present in the seven remaining specimens from that older collection. Ventral color in recently collected adults is uniformly bluish yellow (Fig. 2 F), but some of the specimens from 1956 have each scale either pale gray or yellow anteriorly and darker gray posteriorly; ventrals of the two juveniles are yellow anteriorly and blue gray posterior to the neck. In recent specimens, the supralabials are typically yellow with brown on the upper portions of the anterior supralabials and black on the same areas of the posterior scales, but are yellow suffused or heavily dusted with brown or gray in the AMNH collection, except for AMNH 76664 and 89362, which are uniformly cream. Infralabials and gulars are typically yellow suffused with some blue gray, except that juveniles BPBM 20844 (SVL = 317 mm) and AMNH 89362 (SVL = 286 mm) are uniformly pale yellow and cream, respectively. Color in life. Paratype BPBM 20844 was recorded as “ Dorsum olive green with black lateral stripe and series of black spots on neck. Series of blue-white lateral spots forming a row of vague diagonal bands on anterior half of body. Iris burnt orange. Supralabials, chin, and throat yellow, changing to olive brown approximately one-fifth way down venter. ” The holotype (Fig. 3 C) was the same but with the entire venter pale yellow-gray, the light spots obviously just interstitial skin, and the tongue dark. BPBM 10446 was noted as having the iris orange and the tongue black; BPBM 20847 and 20848 had the iris orange brown.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	etymology	Etymology. The species name is a compound feminine noun in apposition from the Greek melan -, meaning “ black ”, and the Greek arkys, meaning “ net ”. It refers to the pattern of black margining on the dorsal scales. Range. As currently known, this species is restricted to Rossel Island (Fig. 4). There are a few tiny islets within the fringing reef around Rossel Island that might also be found to contain this species.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	biology_ecology	Ecology. Most of the specimens I obtained came from an area of well-developed secondary rainforest around 280 m a. s. l. that was the site of the former village of Bibikea, which the Australian government forcibly relocated to the coast at the end of World War II. Furthermore, the cyclone of 1993 created an areally extensive landslide from above to below this region that ran from ca. 250 – 600 m a. s. l. The canopy in this area was 25 – 30 m high, and the undergrowth was moderate but not dense; palms, pandanus, and ferns were common. Other specimens came from gardens or secondary forest around the villages of Cheme and Jinjo; presumably the AMNH specimens from Abaleti and Jinjo came from similar disturbed forest, as reported by Brass (1959).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD54D653E7B1FD0D04E5F84F.taxon	discussion	Remarks. As remarked for Dendrelaphis anthracina sp. nov. above, my observations on everted hemipenes do not reveal the terminal half of the organ to be calyculate, nor do I find a transverse ridge separating the large basal spines from the distal field of small spicules (Fig. 8 B), contrary to the report of McDowell (1984) based on dissection of uneverted organs.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD50D65EE7B1FF4C0132FDDF.taxon	description	Figs. 3 D, 8 C, 10, 11	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD50D65EE7B1FF4C0132FDDF.taxon	materials_examined	Holotype. BPBM 17277 (field number FK 6959), adult male, F. Kraus, Bwaga Bwaga ridge camp: 10.6740 ° S, 152.6828 ° E, 440 – 480 m, Misima Island, Milne Bay Province, Papua New Guinea. Paratypes (n = 13). Papua New Guinea: Milne Bay Province: Misima Island: same location as holotype (BPBM 17234); vicinity of Liak, 10.659 ° S, 152.694 ° E, 1 – 80 m a. s. l. (BPBM 17276); along Nulia River, Liak, 10.661 ° S, 152.685 ° E, 1 – 40 m a. s. l. (BPBM 17235); Narian, near mouth of Cornwall Creek, 4 km W Bwagaoia, 0 – 15 m a. s. l. (AMNH 76691 – 94); Misima Mine site, 10.6914 ° S, 152.7958 ° E, 30 m a. s. l. (SAMA R 69248); 10.6644 ° S, 152.8017 ° E, 290 m a. s. l. (SAMA R 69901); 10.6642 ° S, 152.7981 ° E, 270 m a. s. l. (SAMA R 69903, R 69906, R 69911); 10.6742 ° S, 152.8133 ° E, 215 m a. s. l. (SAMA R 69915).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD50D65EE7B1FF4C0132FDDF.taxon	diagnosis	Diagnosis. A moderately large species of Dendrelaphis (adult SVL up to 907 mm, tail up to 390 mm; TL / SVL = 0.31 – 0.34); adult eye approximately equal in diameter to eye-naris distance (EY / EN = 0.87 – 1.11, mean = 1.01); ventrals 177 – 187 in six males, 182 – 193 in eight females; subcaudals 124 – 137 in six males, 121 – 141 in five females; hemipenis with a transverse ridge approximately halfway along its length and a terminal papilla but no awn, ornamented with small spines below the transverse ridge and calyculate above that; dorsum and venter of adults uniformly black (juveniles and subadults may be brown or gray suffused with black or with each scale margined in black); supralabials white heavily dusted or stained with black; infralabials and chin white heavily dusted or stained with black. Comparisons with other species. The complete melanization of adults distinguishes Dendrelaphis atra sp. nov. from all other Melanesian members of the genus except D. anthracina sp. nov. From that species it is distinguished by its hemipenis that lacks the large proximal spines of D. anthracina sp. nov., has a transverse ridge that encircles the entire organ (vs. ridge forms a semicircle on the left side of the sulcus in D. anthracina sp. nov.), and is calyculate distally (vs. with many small spines in D. anthracina sp. nov.). It further differs from that species in details of its color pattern: the dorsum is matte black (vs. glossy black in D. anthracina sp. nov.), and the labials and chin are matte white heavily dusted or stained with black (vs. uniformly glossy white with only a few black markings in D. anthracina sp. nov.). Dendrelaphis roseni sp. nov. is also highly melanized as adults but differs from D. atra sp. nov. in retaining a pale vertebral stripe or vestige of such a stripe, and it has the first dorsal scale row on the anterior body cream whereas D. atra sp. nov. is completely black on all dorsal scale rows. Dendrelaphis calligastra has the same hemipenial structure as D. atra sp. nov. and may be a close relative. However, as noted above, the highly melanized coloration of adult D. atra sp. nov. distinguishes that species from D. calligastra, and all stages of D. calligastra have a distinct black postocular stripe, which is only vaguely suggested by dark pigment along the upper sutures of the supralabials with the postoculars and temporals in juvenile D. atra sp. nov.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD50D65EE7B1FF4C0132FDDF.taxon	description	Description of the holotype. Adult female. Dorsal scale rows 13 - 13 - 11, reduction to 11 rows at ventral 105; all scales smooth. Vertebral scales hexagonal; paravertebral scales elongated, semi-hexagonal; remainder narrowly rhomboidal and oblique to body axis. Rostral half again as wide as high; internasals, frontal, supraoculars, and parietals longer than wide; prefrontals wider than long; lateral extension of parietal contacts upper postocular; nasals divided by large nares, with short dorsal suture extending from anterior of naris to internasal on both sides, short ventral suture extending from anterior of naris to first supralabial on left, and from posterior of naris to first supralabial on right; loreal single, elongate; preocular single, higher than long; postoculars two, upper larger; anterior temporals two, upper shorter than lower; posterior temporals 4 (R) and 5 (L) (Fig. 10). Supralabials 8, 4 th and 5 th below eye; infralabials 9, 4 (R) and 5 (L) contact anterior genials. Posterior genials in contact with infralabials 5 and 6, separated along their posterior half by pair of intergenials; single lateral gular separates posterior genials from infralabial 7. Many small tubercles present in the rostral, nasals, internasals, prefrontals, mental, infralabials, and genials; shallow pits present on loreals, preoculars, postoculars, temporals, supralabials, and lateral edge of parietals. Ventrals 186; cloacal scale divided; subcaudals 91 +; ventrals and subcaudals each with a ventrolateral ridge. Dorsal scales on tail in nine rows at level of cloaca, six rows at third ventral, four rows at midtail, and four rows near tip. Total length 1245 mm; snout-vent length 907 mm; tail length 338 mm, tip missing; mass 87.5 g in life. Dorsal ground color in preservative uniform black; head black; white heavily marked with black on supralabials, infralabials, chin, and first six ventrals; venter black otherwise; ventrals on anterior third of body have some little amount of white on ventrolateral ridges. Iris black. Hemipenis (taken from paratype SAMA 69248). Hemipenis unilobed with transverse ridge at approximately half its length that is small on the asulcate side and which expands into a large shelf on the sulcate side; organ capped with terminal papilla (Fig. 8 C). Sulcus spermaticus narrow, unforked, arising from anteromedial side of base, crossing transverse ridge, and then diverging medially to end just below terminal papilla; lips of sulcus closely adpressed along entire length. Hemipenis widest at transverse ridge, from which it narrows considerably towards terminal papilla. Base of organ nude, then with many small spines to the level of the transverse ridge; above ridge calyculate, with tiny spicules mixed among the calyces. Variation. Available adult specimens vary from 610 – 1055 mm SVL and 887 – 1245 mm total length; the one juvenile (BPBM 17234) and apparent subadult (SAMA R 69915) have SVL = 247 mm and 454 mm and total lengths of 356 mm and 677 mm, respectively. Mensural ratios of potential interest differ little between the sexes, though the smallest specimen (BPBM 17234) has a relatively wider snout than do the adults (Table 5). Females trend toward having slightly more ventrals than males, though there is no apparent difference in numbers of subcaudals between the sexes (Table 5). Variation in other scale counts is minimal. Everted hemipenes are available only for the paratype described above. In all specimens there is no trace of a vertebral stripe, with the vertebral scale row being the same color as the remining dorsal scales. All larger adults (> 690 mm SVL) are uniformly black dorsally (Fig. 11 A); the sole juvenile (SVL = 247 mm) is gray brown; two specimens of intermediate size (SVL = 454 and 610 mm) are gray or brown with each scale margined in black (Fig. 11 C); and a third, slightly larger, specimen 681 mm) is gray with each scale heavily suffused with black. Two of these smallest specimens (BPBM 17234, SVL = 247 mm; BPBM 17235, SVL = 610 mm) have the margin between the posterior supralabials and the lower temporals darker, imparting the impression of a vague, narrow postocular line, though it is not as wide as seen in D. calligastra nor in other species characterized by a postocular stripe; that of BPBM 17235 is the best developed. Similarly, the venter of all larger adults is uniform black with a white chin (Fig. 11 B); the juvenile is lighter gray brown ventrally; the two specimens of SVL = 454 and 610 mm are blue-gray or pale gray-brown with black spots, streaks, or flecks (Fig. 11 D); and the slightly larger specimen of 658 mm SVL is gray heavily suffused with black. Clearly, this species undergoes progressive ontogenetic melanization both dorsally and ventrally. Similar melanization occurs progressively on the chin and labials, with smaller specimens having less black: SAMA R 69915 (SVL = 454 mm) has uniformly cream gulars and infralabials, and the supralabials are cream narrowly margined dorsally with black; the smaller BPBM 17234 (SVL = 247 mm) has cream supralabials though the gulars and infralabials are heavily dusted with black. All adults have labials and gulars white heavily dusted or stained with black, and AMNH 76691 even has the supralabials uniformly black, and AMNH 76693 – 94 have them almost entirely black. Color in life. As seen in photos of the holotype, adults are uniform black in life with labials and chin white dusted with black (Fig. 3 D).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD50D65EE7B1FF4C0132FDDF.taxon	etymology	Etymology. The species name is a feminine Latin adjective meaning “ black ”. Range. Restricted to Misima Island (Fig. 4).	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD50D65EE7B1FF4C0132FDDF.taxon	biology_ecology	Ecology. Two of my specimens came from the general area of a village at sea level and two from rainforest along a ridge at 440 m elevation. The four AMNH specimens also came from the vicinity of a village near sea level. The SAMA specimens came from a mix of remnant primary rainforest, secondary forest, gardens, and severely degraded human-modified habitats at a mine site, including alongside a building.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
5C0DC869AD5ED65CE7E1FEB4008DFA43.taxon	discussion	and I recognize ten, it seems useful to provide an updated key to the species in that region. I exclude the two species (D. keiensis, D. striolatus) clearly extralimital to Melanesia, for which the key provided by van Rooijen et al. (2015) is sufficient. Van Rooijen et al. (2015) also considered D. punctulatus to be restricted to Australia and, hence, extralimital to Melanesia, and they placed all New Guinean snakes formerly assigned to D. punctulatus in D. macrops. However, snakes I have collected from eastern Papua New Guinea do not accord with D. macrops and presumably represent true D. punctulatus. This issue requires further investigation, but in the meantime I conservatively include D. punctulatus in the key below.	en	Kraus, Fred (2025): New species of snakes of the genus Dendrelaphis (Squamata: Colubridae) from the Milne Bay Islands, Papua New Guinea. Zootaxa 5618 (4): 451-480, DOI: 10.11646/zootaxa.5618.4.1, URL: https://doi.org/10.11646/zootaxa.5618.4.1
