Spondylurus sloanii ( Daudin 1803 )

Hedges, S. Blair & Conn, Caitlin E., 2012, A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae) 3288, Zootaxa 3288 (1), pp. 1-244 : 201-207

Spondylurus sloanii ( Daudin 1803)

Virgin Islands Bronze Skink

( Figs. 73E , 76C , 81 )

Scincus sloanii — Daudin, 1803:287. Holotype by monotypy; holotype number and type-locality not stated.

Scincus sloanei — Merrem, 1820:70.

Spondylurus sloanei — Fitzinger, 1826:23.

Tiliqua sloanii —Gray, 1831:70.

Scincus richardi —Cocteau, 1837 (mentioned in Gray [1839:292] and in Duméril and Bibron [1839:639]; same specimen as type of Scincus sloanii Daudin ; two brief extracts published by Cocteau [1837a,b] but apparently the full manuscript, with names, was never published).

Tiliqua richardi —Gray, 1838:292 (same specimen as type of Scincus sloanii Daudin ).

Tiliqua sloanii —Gray, 1838:293.

Eumeces sloanii — Duméril & Bibron, 1839:639 (redescription of holotype of Scincus sloanii Daudin and restriction of typelocality to “ Saint-Thomas,” collected by " Richard père" = Louis Claude Richard, probably in 1781–89; see Remarks) .

Mabouya sloanei — Gray, 1845:94 ( Jamaica, in error).

Mabuia cuprescens — Cope , 1862:186 (St. Thomas; holotype apparently lost) .

E[uprepes] semitaeniatus — Peters, 1871:400 (part).

Mabuya sloanii — Bocourt, 1879:401 (part).

Mabuia sloanii — Garman, 1887 ( Jamaica, in error; following Gray[1845]).

Mabuia nitida — Garman, 1887:51 (part, inferred).

Mabuia sloanii — Boulenger, 1887:193 (part, inferred).

Mabuia sloanii — Meerwarth, 1901:37.

Mabuya sloanii — Stejneger, 1904:608 (part).

Mabuya sloanii — Barbour, 1914:320 (part).

Mabuya sloanii — Schmidt, 1928:121 (part).

Mabuya sloanii —Barbour, 1930:105 (part).

Mabuya mabouia — Barbour, 1935:129 (part).

Mabuya mabouya sloanii — Dunn, 1936:544 (part).

Mabuya mabouia — Barbour, 1937:147 (part).

Mabuya sloanii — Grant, 1937:517 (part).

Mabuya mabouya sloanei — Schwartz & Thomas, 1975:141 (part).

Mabuya mabouya sloanei — MacLean et al., 1977:30–34 (part).

Mabuya mabouya sloanei — Heatwole et al., 1981:34 (part).

Mabuya mabouya sloanii — Brygoo, 1985:101 (part).

Mabuya mabouya sloanei — Schwartz & Henderson, 1988:151 (part).

Mabuya mabouya sloanei — Schwartz & Henderson, 1991:457 (part).

Mabuya bistriata — Powell et al., 1996:82 (part).

Mabuya sloanii — Mayer & Lazell, 2000:883 (part).

Material examined (n = 24). British Virgin Islands. KU 242065–70 , Albert Schwartz, Peter Island (Little Harbour), 13 August 1964 ; MCZ R-158940, James Lazell, Little Tobago Island, 27 March 1980 ; MCZ R-178430, P. Gagne, Norman Island (The Bight), 21 October 1993 ; MCZ R-182273, C. O’Connell, Peter Island (Stoney Bay), 17 July 1988 ; UMMZ 74427 , Chapman Grant, Salt Island , 10–17 August 1932 . U.S. Virgin Islands. MNHN 554 Chapman Grant , Capella Island, 29 April 1936 ; UMMZ 239605 , Chapman Grant, Little Buck Island , 18 April 1932 ; USNM 576305 , 576306–576309 (mother and 4 well-developed fetuses), Daniel Nellis , Little Saba Island, 22 April 2004 ; KU 242175, Albert Schwartz, Water Island , Eastside, 25 July 1964 ; ZMUC-R 761–763 , A. H. Riise, St. Thomas , accessioned 1862. West Indies . ZMUC-R 760 , A. H. Riise , accessioned 1862 .

Material not examined (n = 2). U.S. Virgin Islands. MNHN 1088 , from St. Thomas (no specific locality), described and figured by Bocourt (1879) (this specimen was collected before 1879 and, based on low accession number, probably in the late 18th or early 19th century); holotype of Mabuia cuprescens Cope (1862) , from St. Thomas (no specific locality), collected by " A. H. Rüse," no date or catalog number given, type apparently lost (probably collected by Albert Heinrich Riise around 1862, but between 1838–1862; see Remarks) .

Diagnosis. Spondylurus sloanii is characterized by (1) maximum SVL in males, 71.6 mm; (2) maximum SVL in females, 88.9 mm; (3) snout width, 2.10–3.11% SVL; (4) head length, 15.2–19.2% SVL; (5) head width, 11.8– 13.9% SVL; (6) ear length, 1.12–1.73% SVL; (7) toe-IV length, 8.05–11.2% SVL; (8) prefrontals, two (95%), four (5%); (9) supraoculars, three (2%), four (98%); (10) supraciliaries, three (5%), four (95%); (11) frontoparietals, two; (12) supralabial below the eye, five (18%), six (77%), seven (5%); (13) nuchal rows, one (15%), two (75%), three (10%); (14) dorsals, 59–64; (15) ventrals, 58–68; (16) dorsals + ventrals, 118–131; (17) midbody scale rows, 32–34; (18) finger-IV lamellae, 10–13; (19) toe-IV lamellae, 14–17; (20) finger-IV + toe-IV lamellae, 24–30; (21) supranasal contact, Y (95%), N (5%); (22) prefrontal contact, Y (33%), N (67%, although nearly all in near contact); (23) supraocular-1/frontal contact, Y (38%), N (62%); (24) parietal contact, Y (95%), N (5%); (25) pale middorsal stripe, Y; (26) dark dorsolateral stripe, Y; (27) dark lateral stripe, Y; (28) pale lateral stripe, N (or weak); and (29) palms and soles, pale ( Tables 3–5).

Spondylurus sloanii differs from S. caicosae sp. nov., S. fulgidus , S. haitiae sp. nov., S. macleani , S. magnacruzae sp. nov., S. martinae sp. nov., S. nitidus , S. powelli sp. nov., S. spilonotus , and S. turksae sp. nov. by having a narrower middorsal stripe (1.11–2.42% SVL versus 2.61–10.4% in those other species). It differs from all other species except S. anegadae sp. nov., S. culebrae sp. nov., S. lineolatus , S. monae sp. nov., S. monitae sp. nov., and S. semitaeniatus by having a higher dark dorsolateral stripe width/middorsal stripe width ratio (1.09–2.96 versus 0.115 –0.916 in those other species; Fig. 79 ). Spondylurus sloanii is distinguished from S. lineolatus and S. turksae sp. nov. by having a higher number of midbody scale rows (32–34 versus 26–30 in those other species). From S. macleani , it differs by having distinct dark lateral stripes (versus dark lateral stripes barely evident or absent in S. macleani ). It is separated from S. fulgidus by having a higher number of dorsals (59–64 versus 52–58). From S. haitiae sp. nov., it differs by having fewer ventral scales (58–68 versus 69–72 in S. haitiae sp. nov.). From S. monae sp. nov., it differs by having a taller rostral scale: rostral height/length 1.26–1.71 versus 0.84–1.01 in S. monae sp. nov. ( Fig. 61 ). It is separated from S. monitae sp. nov. by having straighter dark dorsolateral stripes (versus dark dorsolateral stripes that bow inward on the parietal scales in S. monitae sp. nov.; Fig. 73A, E ) and in having a high frequency (95%) of supranasal contact (versus no contact in S. monitae sp. nov.). Additionally, S. sloanii is a larger species ( maximum SVL 88.9 mm) than S. anegadae sp. nov., S. caicosae sp. nov., S. fulgidus , S. haitiae sp. nov., S. lineolatus , S. macleani , S. martinae sp. nov., S. monae sp. nov., S. powelli sp. nov., S. semitaeniatus , and S. turksae sp. nov. ( maximum SVL 63.7–85.9 mm in those other species). Spondylurus sloanii differs from S. anegadae sp. nov., S. fulgidus , S. haitiae sp. nov., S. magnacruzae sp. nov., S. monae sp. nov., S. monitae sp. nov., S. spilonotus , and S. turksae sp. nov. by having fewer total lamellae (190–198 versus 202–238 in those other species), although sample sizes are lower for this character ( Table 4).

Within the Genus Spondylurus , S. sloanii is separated from most species by having a high frequency (67%) of prefrontal contact or near contact (prefrontal separation within 0.3% SVL = ~ 0.2 mm). One-third of specimens (eight of 24) have contact between prefrontals, which is generally rare in Mabuyinae (6% overall). In other species of Spondylurus , prefrontal contact is common only in S. fulgidus (52%) and S. haitiae sp. nov. (50%); uncommon or rare in S. anegadae sp. nov. (3%), S. lineolatus (11%), S. martinae sp. nov. (11%), and S. powelli sp. nov. (25%); and not observed in S. caicosae sp. nov., S. culebrae sp. nov., S. macleani , S. magnacruzae sp. nov., S. monae sp. nov., S. monitae sp. nov., S. nitidus , S. semitaeniatus , S. spilonotus , and S. turksae sp. nov.

From its closest relative, S. culebrae sp. nov. ( Fig. 55C ), S. sloanii ( Fig. 73E ) is distinguished by having shorter dark dorsolateral stripes (tapering at or before forelimbs versus posterior to forelimbs), shorter dark lateral stripes (extending to midbody versus to hindlimbs), in having limbs with only small dark spots (boldly mottled or nov.) and is a smaller species, with a mean of 70.8 mm SVL (19 adults) compared with S. culebrae sp. nov. (mean = 82.1 mm SVL, 45 adults).

The molecular phylogeny ( Fig. 5 ) shows that Spondylurus sloanii is closer, genetically, to S. culebrae sp. nov., S. macleani , and S. monitae sp. nov. than it is to S. semitaeniatus , but the greatest confusion in identification will likely be with the latter species because the two ( S. sloanii and S. semitaeniatus ) appear superficially similar and occur in close proximity and sympatry in the Virgin Islands. The most reliable character in separating these two species is the width of the dark dorsolateral stripes compared with the pale middorsal stripe as measured at the forelimbs instead of the normal location for this measurement, at the ears ( Fig. 80A ). In both species, the dark dorsolateral stripes taper posteriorly until they eventually disappear. However, in S. sloanii , the dark dorsolateral stripes start tapering more quickly, before the forelimbs (e.g., compare pattern in Fig. 78E with that in Fig. 81F ). The dark dorsolateral stripe/middorsal stripe ratio is 0.43–1.08 in S. sloanii and 1.25–2.68 in S. semitaeniatus . A second useful character in separating the two species, although not 100% diagnostic, is prefrontal separation, already noted above. More than two thirds of S. sloanii have contact between prefrontals, or are within 0.3% SVL of contact, versus all S. semitaeniatus with> 0.3% separation of prefrontals ( Figure 80B ). In other aspects of pattern, adult S. sloanii usually differ from S. semitaeniatus in having a pale middorsal stripe that is darker than the pale dorsolateral stripes (versus the same color as the dorsolateral stripes in S. semitaeniatus ), a dorsum with darkedged scales giving a braided appearance (versus lacking a braided appearance in S. semitaeniatus ), and in lacking a pale lateral stripe, or having one that is barely evident (versus having a distinct pale lateral stripe in S. semitaeniatus ). Both species have been described as bronze or coppery, and more observations are needed, but the color of living and preserved S. sloanii appears to be more bronze or coppery than that of S. semitaeniatus .

Description of holotype ( Fig. 81A–C ). The following is based on examination of photographs supplied by MNHN (I. Ineich, personal communication). Absolute measurements could not be taken accurately from the photos, but diagnostic pattern ratios were scorable. An unsexed adult in moderate state of preservation, with broken tail—complete when examined by Duméril and Bibron (1839) —cuts to jaw, and an abdominal slit. SVL 64.0 mm ( Brygoo 1985); tail length not measured (broken); ear-opening large in size and round; toe length order not recorded.

Head scalation. Rostral wider than high, contacting first supralabials, nasals and supranasals. Paired supranasals in median contact, contacting anteriormost loreal. Frontonasal biconvex, wider than long, laterally in contact with anterior loreal scale. A pair of quadrilateral prefrontals, in contact medially, and in contact with frontonasal, both anterior and posterior loreals (which appear to be fused), first supraciliary, first and second supraoculars, and frontal. Frontal hexagonal, oblong and semi-lanceolate, in contact with the second supraoculars and paired frontoparietals. Frontoparietals also in contact with parietals and interparietal. Interparietal tetragonal, near-triangular, separated from nuchals by parietals; parietal eye not distinct. Parietals in contact with upper secondary and tertiary temporal scales. Four supraoculars, the second one being the longest and largest. Four supraciliaries, the second the longest. Nostril in posterior part of the nasal. A small postnasal, bordered by supranasal, anterior loreal and first supralabial. Anterior and posterior loreals fused into one roughly rectangular scale. Two or three upper preoculars and two lower preoculars. A single row of small scales across the dorsal edge of the eyelid window. Eight supralabials, the sixth being the widest and forming the lower border of the eyelid. Five moderately enlarged scales behind eye comprising the postoculars; similar to temporal scales but smaller (except for one large primary postocular). One primary temporal, two secondary temporals, and three tertiary temporals; all imbricate, smooth, cycloid, not distinctly delimited from the scales on the nape and the sides of the neck. Seven infralabials. Mental scale wider than long, posterior margin curved slightly toward tip of snout. Postmental scale and two pairs of adjoining chin shields in contact with anterior infralabials. First pair of chin shields in contact medially; second pair damaged; third pair separated by a smaller cycloid scale.

Body and limb scalation. Two rows of paired nuchal scales. Other scales on nape similar to dorsals. On lateral sides of neck, scales slightly smaller. Dorsal scales cycloid, imbricate, smooth, not counted; ventrals similar to dorsals; not counted; scales around midbody not countable in photographs. No distinct boundaries between dorsals, laterals and ventrals. Scales on tail and limbs similar to dorsals, except smaller on limbs. Palmar and plantar regions with small tubercles, subequal in size and delimited by a surrounding region of flatter scales. Subdigital lamellae smooth, single, not countable on finger-IV or toe-IV. Preanal scales similar to ventrals. No enlarged

Pattern and coloration. Dorsal ground color medium brownish-gray with small dark brown spots, distributed on body and limbs. Dark dorsolateral stripes present, wide at ear level, dark brown, extending from the nuchal scales (anterior to which the pattern is no longer visible because external, pigmented layer of scales is missing on most of head) to first third of body, tapering distinctly anterior to forelimbs. The dark dorsolateral stripe/middorsal stripe ratio at ear level is 2.45 and at forelimbs is 0.658. Dark lateral stripes present, dark brown, visible from behind eye to first third of body (although faded and difficult to discern). Pale middorsal stripe present, narrow at ear level, medium brownish-gray, visible from nuchal scales to first third of body. Pale dorsolateral stripes present, pale gray, visible from nuchal scales to first third of body. Pale lateral stripes absent. Ventral surface of body without pattern. Palmar and plantar surfaces unpigmented. No information is available on color in life; however, color and pattern of the 230–222-year-old specimen was described by Duméril and Bibron (1839) only ~50 years after it was preserved. They recorded a greenish-bronze dorsum with two black dorsolateral stripes beginning on the supraocular region and ending in the first half of the back and replaced with a series (lines) of black dots on the second half of the back. The lateral stripes were described as similarly fading into a double or triple series of dots and extending to the hindlimbs. The venter was recorded as glossy greenish-gray. Of possible diagnostic importance is their comment that scales not colored black have a light brown edge. This was also noticed in the recently collected specimens from Little Saba ( Fig. 81E ) and conveyed an overall braided appearance not seen in Spondylurus semitaeniatus .

Variation. In pattern and scalation, most specimens resembled the holotype, with dorsal ground color varying from grayish-brown to greenish-brown ( Tables 4–5). Limbs appear slightly darker than body. Dark dorsolateral stripes taper before the forelimbs and dark lateral stripes extend one-third of body or midbody. Pale lateral stripes, which are present in most species of Spondylurus , are absent (or weakly defined) in S. sloanii . Albert Schwartz recorded the color in life of Peter Island specimens as having a "tannish-brown" and "not metallic" dorsum, pale stripes "creamy" anteriorly, and venter "pale yellowish-tan"; he described the Water Island specimen as having its dorsum "tannish bronze," pale dorsolateral stripes "dull creamy," and venter "dirty cream." The color in life of the large adult from Little Saba is bronze or coppery (e.g., Fig. 81F ). Overall, we find that S. sloanii tends to be more bronze and coppery than S. semitaeniatus , which is usually tan (greenish in preservative), although more information on color in life is needed. The greenish or bluish color seen in preserved specimens is an artifact of preservation.

Distribution. The species is known from the British and U.S. Virgin Islands ( Fig. 10E ). In the British Virgin Islands it is known from Little Tobago, Norman Island, Peter Island, and Salt Island. From the U.S. Virgin Islands it is known from St. Thomas and its islets of Capella Island, Little Buck Island, Little Saba Island, and Water Island.

Ecology and conservation. The species has not been recorded from St. Thomas since 1862, although it still likely occurs on the smaller mongoose-free islands within its distribution. The most recent sighting of the species (2004) was on Little Saba. There, the habitat is mostly coastal shrub with introduced Guinea Grass Panicum maximum , Turks Cap Cactus Melocactus intortus , and the shrub Oplonia spinosa , interspersed with Sea Grape Coccoloba uvifera . This habitat can be described as low shrubby vegetation or grass, including exposed rocky areas and occasional beaches (R. Platenberg, personal communication). Little Saba is a wildlife refuge, but its small size—essentially constituting one population of the skink—and presence of introduced mice pose a threat (R. Platenberg, personal communication). Albert Schwartz found the Peter Island specimens under objects (leaves, rocks) near the coast, and the Water Island specimen under driftwood on a cobble beach. Molecular phylogenetic analyses are needed to determine whether the skinks from these diverse islands all belong to Spondylurus sloanii , as they appear to based on morphology. Also, the current existence of the skink on Water Island, known from a single specimen collected in 1964, should be verified in that the mongoose apparently was released there between 1930 and 1983 ( Barbour 1930a; Horst et al. 2001).

Based on IUCN Redlist criteria ( IUCN 2011), the conservation status of Spondylurus sloanii is Endangered (EN A2ace). It faces a primary threat from the introduced mongoose, which probably led to its extirpation on St. Thomas and other islands on which it may have occurred (e.g., St. John, St. Croix) and are now inhabited by mongooses. Secondary threats include habitat destruction from agriculture and urbanization, and predation from other introduced mammals, including black rats. Studies are needed to determine the health of remaining

Reproduction. The female collected on 22 April 2004 (88.9 mm SVL) contained four developing young ( Fig. 81G ). They measured 24.1–30.2 mm SVL and appeared nearly fully developed. The female collected 18 April 1932 (77.6 mm SVL) also contained four young.

Etymology. The species ( sloanii ) was named in honor of Sir Hans Sloane (1660–1753), a British physician who studied the natural history of the West Indies, describing a skink from Jamaica which Daudin (1803) believed to be the same species as the specimen he described from St. Thomas.

Remarks. Spondylurus sloanii is the second oldest name in the Subfamily Mabuyinae , recognized as a valid species here, and, as expected, it has had a long and confused history. Daudin (1803) described the species based on a visit to the MNHN in Paris, where he saw the specimen. He did not mention locality or catalog number—not uncommon at that time—but focused rather on its unusual appearance (to him) in having three (pale) stripes. He compared it with other lined skinks, citing descriptions in Schneider (1799, 1801). He mentioned that it was brownish above and whitish below, with four dark stripes starting at the snout tip and continuing to the mid-body. Of importance here (diagnostically) is that he stated that two dark stripes, "a little more narrow, continue to the mid-back" (English translation). Such narrow, dark dorsolateral stripes distinguish S. sloanii from skinks on most of the remaining Virgin Islands ( S. semitaeniatus ), where the dorsolateral stripes are more similar in width to the lateral stripes. Daudin also illustrated the holotype, which shows a wide dark lateral stripe and narrow dark dorsolateral stripes. Daudin (1803) compared the specimen with a Jamaican skink described and figured by Sir Hans Sloane in his book on the natural history of Jamaica ( Sloane, 1725), hence Daudin's (1803) recognition of Sloane in the name of the species. This apparently led Gray (1845) to state that the species was confined to Jamaica, an error repeated by Garman (1887), although it had been corrected by Duméril and Bibron (1839).

Duméril and Bibron (1839) cleared up some of the confusion by describing the type specimen in the MNHN more thoroughly and stating the locality (" Saint-Thomas ") and collector: "Richard père." Richard père was almost certainly Louis Claude Richard (1754–1821), a French botanist who collected plants in French possessions in the Americas, including the Caribbean islands, during 1781–89 and then returned to France (Anonymous 2011). This information constrains the date of collection of the holotype of Spondylurus sloanii to 1781–89, about a decade before it was examined by Daudin (1803) for the description.

Duméril and Bibron (1839:642) noted that their description "is from the same individual" described by Daudin, thus fixing the type-locality and collector; confirmed later by Bocourt (1879) and by the similarity in SVL measurements given by Daudin (~ 66 mm, converted), Duméril and Bibron (65 mm), and Brygoo (1985) (64 mm). Even prior to Duméril and Bibron (1839), Gray (1831) described Tiliqua richardi based on the same specimen (Daudin's holotype), indicating it was from St. Thomas and in the Paris Museum. That specimen exists today and is MNHN 554, a number that first appeared in the literature much later ( Schwartz & Thomas 1975; Brygoo 1985; Schwartz & Henderson 1988; Miralles 2005). Bocourt (1879):plate 22B, figure 3) did not mention the specimen catalog numbers but illustrated two specimens of Spondylurus sloanii Daudin : one from " Saint-Thomas " and the other "collected by Richard père" (showing only head scales). The text of Bocourt and records of the MNHN show that the specimen illustrated from " Saint-Thomas " is MNHN 1088, obtained from the Museum of Copenhagen, and the specimen collected by Richard père is the holotype, MNHN 554. Bocourt's illustration of MNHN 1088 shows relatively narrow dark dorsolateral stripes and point contact of prefrontals, which agrees with St. Thomas material and not S. semitaeniatus . The second (holotype) shows broad contact of prefrontals, again agreeing with other St. Thomas material (i.e., Cope's lost holotype of Mabuia cuprescens and recent material from St. Thomas). The holotype was also illustrated by Miralles (2005) and photographs of it are shown here ( Fig. 81A–C ).

The molecular phylogeny ( Fig. 5 ) also supports the species distinction of Spondylurus sloanii and S. semitaeniatus : S. sloanii (represented in the tree by three specimens from Little Saba) is more closely related to S. macleani , S. culebrae sp. nov., and S. monitae sp. nov. than to S. semitaeniatus . The diagnostic characters in the types of S. sloanii and S. semitaeniatus ( Fig. 80 ) agree with the specimens used in the molecular phylogenies and other material assigned here to those species. Nonetheless, more material of S. sloanii is needed to better characterize the species. Of the 18 adults of S. sloanii that we had available, two (ZMUC-R 761 and USNM 576305) were larger (86 and 89 mm SVL, respectively) than all 64 of the S. semitaeniatus we examined (83 mm SVL, maximum), suggesting that it is a larger species. In coloration, the fresh adult specimen, USNM 576305, and its four well-developed fetuses (USNM 576306–309) differ from S. semitaeniatus in having a bronze, braided

Another question concerns the status of the mabuyine skinks on the islands of Water, Capella, and Little Buck off of St. Thomas (Little Buck should not be confused with Buck island off of St. Croix). Little Buck and Little Saba are both only about 3–4 km away from St. Thomas, and Water Island is even closer (500 m). Although it may seem unusual that different species of skinks inhabit these small islets of St. Thomas, the alsophine snakes of those islands show taxonomic differentiation as well: Little Saba and Water Island share with St. Thomas the subspecies Borikenophis portoricensis richardi whereas Little Buck has a different (endemic) subspecies, B. p. nicholsi ( MacLean 1982; Schwartz & Henderson 1991; Hedges et al. 2009).

Cope (1862a) described Mabuia cuprescens based on a specimen from St. Thomas, obtained from "Mr. A. H. Rüse," now apparently lost. The collector was undoubtedly Albert Heinrich Riise (1810–1882), a prominent Danish pharmacist and naturalist active in St. Thomas after his arrival in 1838, thus dating the collection between 1838–1862. Cope's description accurately pertains to S. sloanii , including the character he noted as being important: frontal scale not truncate anteriorly. This is another way of saying that the prefrontals are in contact, a character of S. sloanii . Cope also noted the coppery color (hence the species name cuprescens ), which, although certainly not unique to S. sloanii —many skinks are characterized and even named after their metallic, bronzy, or coppery coloration—appears more striking than in the several geographically proximal species. Cope further described the dark dorsolateral bands as being "narrow" (relative to the lateral bands described), which again is consistent with S. sloanii and not S. semitaeniatus .

Figures

FIGURE 5 (continued on the next page)

FIGURE 10. Map showing the distribution of mabuyine skinks occurring on islands in the greater Puerto Rico region. See Figure 1 for location of the islands. The islands and species are: (A) Puerto Rico (Spondylurus nitidus); (B) Mona (Spondylurus monae sp. nov., squares) and Monito (Spondylurus monitae sp. nov., circle); (C) Desecheo (Spondylurus nitidus); (D) Vieques (Spondylurus nitidus, circle), Culebra (Spondylurus nitidus, circles; Spondylurus culebrae sp. nov., squares), Cayo Luis Peña and Cayo Norte (S. nitidus, circles); (E) most of the U.S. and British Virgin Islands (Spondylurus macleani, diamond; Spondylurus sloanii, squares; Spondylurus semitaeniatus, circles; Spondylurus spilonotus, triangles); (F) Anegada (Spondylurus anegadae sp. nov.); and (G) St. Croix and Green Cay (Capitellum parvicruzae sp. nov., circle; Spondylurus magnacruzae sp. nov.,

FIGURE 55. Representative patterns in species of the Genus Spondylurus (top, dorsal view; bottom, side view). (A) S. anegadae sp. nov.; (B) S. caicosae sp. nov.; (C) S. culebrae sp. nov.; (D) S. fulgidus; (E) S. haitiae sp. nov.; (F) S. lineolatus; (G) S. macleani; (H) S. magnacruzae sp. nov.; (I) S. martinae sp. nov.; and (J) S. monae sp. nov.

FIGURE 61. Graph of rostral height versus rostral length in seven species of the Genus Spondylurus.

FIGURE 73. Representative patterns in species of the Genus Spondylurus (top, dorsal view; bottom, side view). (A) S. monitae sp. nov.; (B) S. nitidus; (C) S. powelli sp. nov.; (D) S. semitaeniatus; (E) S. sloanii; (F) S. spilonotus; and (G) S. turksae sp. nov.

FIGURE 76. Head scalation in species of the Genus Spondylurus (left, side view; right, dorsal view). (A) S. powelli sp. nov. (MCZ R-74343, holotype); (B) S. semitaeniatus (UMMZ 80585); (C) S. sloanii (USNM 576305); and (D) S. spilonotus

FIGURE 78. Spondylurus semitaeniatus, from the Virgin Islands. (A–D) ZMB 1238, holotype, restricted to St. John, U.S.

FIGURE 79. Graph of pale middorsal stripe width versus dark dorsolateral stripe width in 16 species of the Genus Spondylurus.

FIGURE 80. Graphs showing characters distinguishing Spondylurus semitaeniatus and S. sloanii. (A) Graph of dark

FIGURE 81. Spondylurus sloanii, from the Virgin Islands. (A–C) MNHN 554, holotype, St. Thomas, U.S. Virgin Islands. Photographs courtesy of Ivan Ineich. (D–F) USNM 576305, Little Saba Island, St. Thomas (F = live). (G) fetus of USNM 576305.