Calcinus mclaughlinae, Poupin & Bouchard, 2006

Poupin, Joseph & Bouchard, Jean Marie, 2006, The eastern Pacific species of the genus Calcinus Dana, 1851, with description of a new species from Clipperton Island (Decapoda, Anomura, Diogenidae), Zoosystema 28 (2), pp. 465-486 : 474-480

Calcinus mclaughlinae n. sp.

( Fig. 4 )

Calcinus ? californiensis – Chace 1962: 627, figs 5, 6 [ Clipperton]. — Haez et al. 1966: 29. —? Haig et al. 1970: 16. —? Ball & Haig 1974: 101 [part]. — Hendrickx & Harvey 1999: 368 [part]. —? Hernández Aguilera 2002: 312. Non C. californiensis Bouvier, 1898 .

TYPE MATERIAL. — Clipperton I. Jean-Louis Étienne Expedition, outer reef, low tide and snorkeling 1-2 m, II.2005, coll. J. Poupin, holotype, 1 ♂ 4.4 mm (MNHN- Pg 7620).

Paratypes: same data, 10 ♂♂ 2.0- 4.4 mm, 7 ovig. ♀♀ 2.0-3.0 mm ; 2 ♀♀ 1.6-2.2 mm; 4 specimens in shells (MNHN-Pg 7621).

TYPE LOCALITY. — Clipperton Island.

ETYMOLOGY. — This species is dedicated to Patsy A. McLaughlin for her invaluable contributions to the systematics of the anomura. Her warm support to the first author when working at MNHN was a strong encouragement to continue in this field of research.

OTHER MATERIAL EXAMINED. — Clipperton I. Jean- Louis Étienne Expedition, outer reef, low tide, stn 4, 10°18.11’N, 109°14’W, 9.I.2005, coll. L. Albenga, J. M. Bouchard, L. Dugrais, and J. E. Blatteau, 2 ♂♂ 4.4-5.0 mm ; 1 ovig. ♀ 2.5 mm; 5 specimens in shells (MNHN-Pg 7622). — Outer reef, scuba dive, 15 m, stn 8, 10°18.49’N, 109°14.1’W, 14.I.2005, 2 specimens in shells (MNHN-Pg 7623). — Outer reef, stn 20, 10°17.50’N, 109°13.55’W, 22.I.2005, 1 specimen in shell (MNHN-Pg 7624). — Scuba dive, 20 m, stn 41, 10°19.01’N, 109°13.75’W, 29.I.2005, 1 ♂ 1.5 mm (MNHN-Pg 7625). — Scuba dive 22 m, stn 45, 10°17.49’N, 109°13.52’W, 3.II.2005, 1 specimen in shell (MNHN-Pg 7626). — Coll. Centre de Recherche et Service de Santé des Armées, 2 ♂♂ 2.3-2.4 mm (MNHN-Pg 634). — Leg. Chace USNM, coll. 1958, 5 ♂♂ ; 5 ♀♀ (MNHN-Pg 631). — NW end reef, 14.VIII.1958, coll.Limbaugh, Chess, Reese, Hambly, and Wintersteen, size range males 1.3-4.2 mm, ovig. females 2.0- 4.7 mm, females 1.4-3.0 mm, 1 ♂; 1 ovig. ♀ ( USNM 110896 ). — Rocky intertidal areas, 7-26.VIII.1958, 39 ♂♂ ; 2 ovig. ♀♀; 30 ♀♀ ; 1 juvenile ( USNM 110987 ). — NE side, 14 m (45 ft), 28.VIII.1958, 4 ♂♂ ; 1 ovig. ♀; 1 ♀ ( USNM 110900 . — NE corner, 14 m (45 ft), 30.VIII.1958, 2 ♂♂ ; 1 ovig. ♀ ( USNM 110897 ). — NE side, low intertidal to 2 m (6 ft), 4.IX.1958, 1 ♀ ; 2 juveniles ( USNM 110898 ). — Reef flat 0-0.3 m (1 ft), 13.IX.1958, 1 ♂ ( USNM 110901 ). — East side reef flat, 14.IX.1958, 1 ovig. ♀ ( USNM 110899 ) .

West coast of Baja California Sur (see Remarks). Coll. A. W. Anthony, 23 ♂♂ 3.2-7.0 mm ; 10 ovig. ♀♀ 2.8- 5.6 mm; 4 ♀♀ 3.7-5.0 mm ( USNM 42550 ) .

DISTRIBUTION. — Clipperton Island, possibly Socorro I., and west coast of Baja California Sur.

HABITAT. — Lower intertidal to 22 m; on coral Pocillopora , and rubble. At Clipperton, usually found deeper than C. explorator , although the two can be found together.

DIAGNOSIS

Ocular acicle terminating in one or occasionally two or three spines. Upper margin of right chela smooth. Outer face of left chela regularly convex. Dactyls of P2-P3 with similar setation consisting of sparse, widely-spaced tufts of setae. Propodus of P3 with upper part of outer face flattened or slightly concave, forming low sulcus. Dactyl of P3 0.7 times length of propodus, with six or seven small spines on ventral margin.Telson with posterior lobes each with single terminal spine. Ocular peduncles dark brown to black with white distal band adjacent to corneas. Chelipeds black on meri, carpi, and palms of chelae, with margins bright red; dactyls of left and right chelae bright red, cutting edges white. Ambulatory legs bright red, with distal half of dactyls orange.

DESCRIPTION

Shield about 1.1 as long as broad. Rostrum acute, clearly overreaching level of broadly subtriangular lateral projections; anterior margins between rostrum and lateral projections concave. Anterodorsal plate of branchiostegite with dorsal margin smooth.

Ocular peduncles 0.8-1.0 times as long as shield, slightly constricted medially; peduncles each six times as long as diameter of corneas. Corneas weakly dilated. Ocular acicles well developed, subtriangular, terminating in simple spine, or rarely two or three spines.

Antennular peduncles reaching to distal 0.25- 0.3 of ocular peduncles. Ultimate segment 0.3-0.4 times as long as shield.

Antennal peduncles shorter than antennular peduncle, reaching between midpoint and distal 0.3 of ocular peduncles. First segment with ventrolateral angle produced, bearing two to four spines. Second segment with laterodistal angle produced, terminating in bifid spine; distomesial angle unarmed or with spine. Third segment with strong spine at ventrodistal angle. Fourth segment with dorsodistal spine. Fifth segment unarmed. Antennal acicle reaching beyond proximal margin of fifth antennal segment, terminating in strong spine; dorsolateral margin with one or two spines distally, dorsomesial margin with row of three or four spines.

Left chela ( Fig. 4C ) 0.5-0.7 times as high as long. Dactyl slightly shorter than palm, covered with low granules; cutting edge smooth or with one or two obtuse calcareous teeth; dorsolateral margin smooth. Fixed finger with one submedian obtuse tooth on cutting edge; outer and lower faces with low granules. Palm with outer face regularly convex, finely granular; lower face with larger tubercles; inner face almost smooth; upper margin smooth. Carpus with prominent submedian tubercle on outer face; upper margin angled, dorsodistal angle unarmed. Merus stout, triangular in cross-section; ventromesial margin unarmed distally; ventrolateral margin with one stout spine distally; upper margin unarmed.

Right chela ( Fig. 4D ) smooth on upper margin of palm. Dactyl about as long as palm; cutting edge with one or two obtuse teeth proximally, distal half spoon-shaped; dorsal surface with low granules. Fixed finger with obtuse tooth on proximal cutting edge; distally hoof-shaped. Palm with outer face weakly convex, slightly granulated; inner face flat, almost smooth. Carpus with smooth upper margin, dorsodistal angle unarmed; outer face with 1 low submedian tubercle. Merus less broad than merus of left cheliped, outer face with numerous small pits, dorsal, ventromesial and ventrolateral margins unarmed distally.

Ambulatory legs similar from left to right P2 ( Fig. 4E ), reaching to tip of left cheliped when fully extended; dactyl 0.5-0.7 times as long as propodus; ventral margin with widely-spaced, sparse tufts of setae and six or seven minute spines; propodus with few long setae, and with or without minute movable spine at ventrodistal angle; carpus 0.5-0.6 times as long as propodus, with dorsodistal spine; merus about as long as propodus, with obtuse laterodistal spine. P3 ( Fig. 4E ) shorter than P2, reaching to base of fixed finger of left chela when fully extended; ventrodistal pilosity similar to that of P2, not brush-like; dactyl 0.6-0.7 times as long as propodus, ventral margin armed with six to eight minute spines; propodus with few setae and one or two minute movable spines at ventrodistal angle, dorsolateral margin angled, upper half of outer face flat to slightly concave, forming a low sulcus; carpus 0.6-0.7 times as long as propodus, with dorsodistal spine; merus 0.8-0.9 times as long as propodus, with obtuse laterodistal spine, sometimes absent.

Fourth pereopod semichelate, bordered with long setae on dorsal and ventral margins. Dactyl terminating in corneous claw; ventrolateral margin with row of spinules. Propodus with broad rasp on outer face consisting of several rows of corneous scales; ventral margin with row of stout spines. Carpus with dorsodistal spine. Merus unarmed. Fifth pereopod chelate, with rasp on propodus and dactyl; carpus and merus unarmed, subovate in cross-section.

Abdomen with four unpaired biramous left pleopods in both sexes. Sixth abdominal tergite calcified, with dorsal face divided into four subequal areas by longitudinal and transverse furrows. Telson with posterior lobes asymmetrical, left more elongated than right; lobes with long setae marginally, each with one posterior spine slightly curved ventrally.

Size range

sl 1.3-5.0 mm; smallest ovigerous ♀ 2.0 mm.

Coloration ( Fig. 4 )

In life, shield black with bright red on margins. Ocular acicles bright red at base, white at tip. Ocular peduncles dark brown to black with white distal band adjacent to corneas. Antennular peduncles dark brown to black, with orange at articulations of segments and distal 0.5 of ultimate segment; flagella orange. Antennal peduncles, flagella, and antennal acicles orange overall. Chelipeds black on meri, carpi, palm of chelae, margins bright red; dactyls of left and right chelae bright red, white on cutting edges. Ambulatory legs bright red, distal half of dactyls orange, terminal claws black. Fifth and fourth pereopods cream to pale orange with darker orange hues on segments. Abdomen tan, sixth abdominal tergite, uropods and telson with scattered orange patches. In preservative coloration of shield ( Fig. 4B ) and outer face of chelae fading quickly to bright red or orange, but color pattern on P2-P3 dactyls still clear after several months.

REMARKS

Calcinus mclaughlinae n. sp. and C. californiensis can be considered sibling species distinguished by subtle differences in colour and morphology.When studying specimens of Calcinus from Clipperton Island, Chace (1962: 628) prudently reported his specimens as “ C.? californiensis ”. These have proved to be C. mclaughlinae n. sp. At that time Chace did not have available coloured specimens from the Mexican mainland for comparison. During the present study, specimens of C. californiensis were collected at Acapulco after the sojourn at Clipperton, and careful comparison of fresh specimens were made from both localities. Calcinus mclaughlinae n. sp. is clearly distinct from C. californiensis by evenly bright red fingers on left chela ( Fig. 4 A-C), and the dactyls of P2 and P3 which are bright red proximally, and orange distally ( Fig. 4E ). All living specimens of C. californiensis collected at Acapulco have the fingers of the left chela black with bright red margins ( Fig. 1C ), and the dactyls of P2 and P3 are evenly bright red ( Fig. 1E ). In the absence of coloration the two species can still be separated by the ocular acicle, with one or rarely two or three spines in C. mclaughlinae n. sp., whereas there are usually two to four spines in C. californiensis . However, as already noted by Chace (1962: 630), this character alone can sometimes be useless because of intraspecific variation.

The coloration of Calcinus mclaughlinae n. sp. is distinct from that of C. explorator ( Figs 3 ; 4 ). However, uncoloured specimens of the two species can be confused because of same aspect of ocular acicle (one terminal spine). The few uncoloured specimens examined herein from the Revillagigedo (Clarión I.) and Cocos I. are very similar to C. mclaughlinae n. sp. by their overall morphology although tentatively assigned to C. explorator (see Remarks under C. explorator ). For the time being, C. mclaughlinae n. sp. can be considered as endemic to Clipperton Island, although it is potentially an “insular endemic” sensu Garth (1960, 1991, 1992) i.e. distributed at least in the Revillagigedo and possibly also in the west coast of Baja California Sur (Punta Cala, Roca de la Vela, Punta Tosca, Magdalena Bay). Calcinus californiensis has previously been reported from these insular localities but has not been compared with live material from Clipperton ( Haig et al. 1970; Ball & Haig 1974; Hernández Aguilera 2002). During the present study, a lot with 37 preserved specimens ( USNM 42550) lacking colour were examined from Baja Magdalena, and are tentatively attributed to C. mclaughlinae n. sp. based on the presence of one spine on the ocular acicles. Two to four spines were observed in all specimens of C. californiensis from the Gulf and Mexican mainland.

Calcinus obscurus Stimpson, 1859 ( Figs 5 ; 6 )

Calcinus obscurus Stimpson, 1859: 83 [type locality: Panama]. — Nobili 1901: 26. — Holthuis 1954: 20, figs 5, 6. — Ball & Haig 1974: 101. — Prahl et al. 1979: 63. — Moran 1984: 74, fig. 6. — Lemaitre & Alvarez-León 1992: 46. — Moran & Dittel 1993: 611. — Hendrickx 1995: 550. — Hendrickx & Harvey 1999: 368. — Boschi 2000: 71.

Non Calcinus obscurus – Schmitt 1924: 170; 1939: 11, 25, 26 = C. explorator Boone, 1930 .

TYPE MATERIAL. — Not seen; probably not extant. Stimpson (1859: 49) indicated that specimens he used had been chiefly supplied from the Museum of the Smithsonian Institution. His syntypes have not been found during this study, and probably were lost in the great Chicago fire of 1871 (see Manning 1993: 112).

MATERIAL EXAMINED (see Remarks for meaning of asterisks). — El Salvador. La Libertad, leg. G. Kruseman, summer 1952, 21 ♂♂ 2.6-8.3 mm ; 9 ovig. ♀♀ 3.1-5.4 mm; 7 ♀♀ 2.2-5.4 mm ( ZMA De 100.355) ; 9 ♂♂ 2.5-7.0 mm; 3 ovig. ♀♀ 3.3-5.0 mm; 1 ♀ 3.0 mm ( RMNH 9399 ). — La Libertad , coll. and leg. John Boursot, 10.XII.1953, 3 ♂♂ 7.5-9.6 mm ( USNM 96289 ) ; VI.1953, 1 ♂ 3.4 mm; 1 ♀ 3.7 mm ( USNM 96316 ). — La Libertad , shore collecting, 18.I.1933, 12 ♂♂ 1.8-5.3 mm ; 12 ovig. ♀♀ 2.3-3.5 mm; 8 ♀♀ 2.8-4.0 mm ( USNM 1076239 ) ; 21.I.1933, 2 ♂♂ 5.5- 5.8 mm; 1 ♀ 4.4 mm ( USNM 1076226 ) .

Costa Rica. Puerto Culebra, shore collecting along S slough, 12.III.1933, 1 ovig. ♀ 2.0 mm (* USNM 1076234). — San Lucas I., coll. & don. M. Valerico, 15.I.1930, 2 ♂♂ 5.4-6.2 mm (* USNM 64134).

Panama. Perico I., coll. Albatross, 26.X.1904, 21 ♂♂ 3.2-6.2 mm ; 6 ovig. ♀♀ 2.9-4.9 mm; 5 ♀♀ 3.1-4.9 mm; several others specimens damaged or in shells ( USNM 40545 ). — Chopilla I., coll. L. G. Abele, 26.V.1969, 3 ♂♂ 7.8-9.8 mm ; 1 ♀ 7.8 mm ( USNM 267603 ) ; 3 ♂♂ 6.4-7.6 mm ( USNM 267600 ) ; 1 ♂ 4.7 mm ( USNM 267593 ) ; 1 specimen in shell ( USNM 267590 ). — Taboguilla I., low tide, coll. L. G. Abele, A. Clarke, T. Dana, J. Graham, G. Powell, and A. Rodaniche, 30.IV.1969, 3 ♂♂ 4.4-6.4 mm ; 1 ♀ 4.9 mm; 1 specimen damaged ( USNM 267556 ) ; 2 ♂♂ 1.8-3.5 mm; 1 ovig. ♀ damaged; 2 ♀♀ 2.0- 3.2 mm ( USNM 267596 ) ; 12.VI.1969, several juveniles in shells ( USNM 267602 ) ; 1 ♂ 3.4 mm ( USNM 267554 ) ; 7.IV.1969, several juveniles, poor condition ( USNM 267598 ). — East end of Panama Boulevard, intertidal, coll. L. G. Abele, 17.II.1969, 3 ♂♂ 1.7-3.7 mm ( USNM 267599 ). — Intertidal , beyond Fort Kobke, Venado Beach, coll. L. G. Abele, A. Clarke and J. Graham, 8.V.1969, 1 ♂ 1.7 mm ( USNM 267594 ) ; 1.VII.1969, 1 ♂ 5.6 mm; 1 specimen in shell ( USNM 267597 ). — Panama city, Punta Paitilla, low tide, coll. L. G. Abele, J. Graham, N. Powell, and A. Soler, 7.VII.1969, 2 juveniles in shells ( USNM 267595 ) ; 7.VII.1969, 16 ♂♂ 2.3-8.1 mm; 4 ovig. ♀♀ 3.3-4.3 mm; 2 ♀♀ 3.0- 3.8 mm; several other specimens in shells ( USNM 267557 ) ; 16.IX.1967, 2 ♂♂ 5.2-5.6 mm ( USNM 267555 ) ; 14.IV.1969, 4 ♂♂ 2.5-4.2 mm; 3 ovig. ♀♀ 4.0- 4.2 mm; 2 ♀♀ 3.5-3.6 mm ( USNM 267592 ) ; 8.VI.1969, 1 ♂ 7.6 mm ( USNM 267553 ) ; 31.XII.1968, 1 ovig. ♀ 3.9 mm ( USNM 267601 ) ; 1.VII.1969, 6 ♂♂ 3.0- 6.5 mm; several others specimens in shells ( USNM 267589 ). — Bay of Panama, coll. F. H. Bradley, 5 ♂♂ 5.0- 8.4 mm ; 1 ♀ 4.2 mm ( USNM 265349 ). — Taboga, coll. Meek and Hildebrand, 12.V.1915, 1 ♂ 6.8 mm ; 1 ovig. ♀ 5.3 mm; 1 ♀ 5.2 mm ( USNM 44192 ) ; coll. E. Deichmann, VII.1924, 1 ♂ 7.0 mm; 1 ♀ 5.3 mm ( USNM 1076231 ) ; shore, low tide rocks, coll. E. Deichmann, V-VII.1924, 1 ♂ 7.8 mm; 1 ♀ 3.0 mm ( USNM 1076243 ) ; 4 specimens in shells ( USNM 1076233 ). — Panama city, coll. and don. “J. Zetek”, I.(?)1914, 5 ♂♂ 3.0- 7.3 mm ( USNM 48794 ). — “ Panama, Geay 1887, det. Forest 1949”, 3 ♂♂ 5.8-6.2 mm (MNHN-Pg 804). — “ Panama ”, 1 ♂ 4.6 mm ( USNM 1076225 ) ; 1 ♂ 8.6 mm (MNHN-Pg 802); 1 ♂ 6.0 mm; 1 ♀ 7.0 mm (MNHN-Pg 803). — Bahia Honda , coll. W. L. Schmitt, stn 111, 9.III.1933, 1 ♂ 1.9 mm (* USNM 1076242 ) ; stn 114, 10.III.1933, 1 ♂ 1.8 mm (* USNM 1076241 ). — “ Panama, Cocos Island ”, coll. Pinchot Exp. 1929, 1 ♂ 4.2 mm ; 1 ovig. ♀ 4.2 mm (* USNM 63162 ) .

Colombia. Port Utria , shore, coll. W. L. Schmitt, stn 418, 23.I.1935, 2 ♂♂ 4.5-5.3 mm ; 2 ovig. ♀♀ 2.7-4.5 mm; 1 ♀ 2.8 mm (* USNM 1076232 ). — Octavia Bay , stn 433, 27.I.1935, 1 ♂ 4.5 mm (* USNM 1076240 ) .

Ecuador. Salinas , 14.IX.1926, 9 ♂♂ 3.8-8.3 mm ; 2 ovig. ♀♀ 6.5-6.8 mm; 3 ♀♀ 2.9-5.2 mm ( USNM 1076227 ) .

Peru. Máncora, intertidal, coll. W. L. Klawe, Inter. Am. Tropic.Tuna Com., 14.VI.1960, 1 ♂ 5.8 mm ; 1 ovig. ♀ 6.4 mm ( USNM 106445 ) ; Máncora, intertidal among stones, “ W. K.Weyrauch no. 12.636”, 23.IV.1959, 4 ♂♂ 4.4-5.7 mm ( RMNH 14833 ) .

West coast of South America. “ Côtes ouest de l’Amérique du Sud, ancien envoi, Patria ignota, 1905, det. G. Nobili ”, 1 ♂ 9.0 mm ; 3 ♀♀ 5.5-7.2 mm (*MNHN-Pg 805).

DISTRIBUTION. — Eastern Pacific, from El Salvador (La Libertad, 13°29’N) to Peru (Máncora, 4°07’S), including Ecuador, Costa Rica, Panama, Colombia and Gorgona Is. Holthuis (1954: 22) reported a doubtful record (reference not indicated) from South California, probably based on C. californiensis . Lemaitre & Alvarez-León (1992: 46) listed “California” in the distribution of C. obscurus , based on Holthuis’ reference. As suggested by Hendrickx & Harvey (1999: 368), this obscure record must be considered erroneous, and the northern limit of C. obscurus more confidently is La Libertad (13°29’N).

HABITAT. — Lower intertidal, among rocks, rubble, or algae; commonly found in large numbers ( Stimpson 1859; Ball & Haig 1974).

DIAGNOSIS

Ocular acicle terminating in two to four spines, or rarely one. Anterodorsal plate of branchiostegite smooth, with one or two spinules subproximally. Upper margin of right chela smooth ( Fig. 5C ). Outer face of left chela regularly convex ( Fig. 5B ). Dactyls of P2-P3 with similar setation consisting of sparse, widely-spaced tufts of setae ( Fig. 5D ). Propodus of P3 with dorsolateral margin weakly angled, upper half of outer face weakly concave. Dactyl of P3 0.5-0.7 times length of propodus, with 6-8 spines on ventral margin.Telson with posterior lobes each with single terminal spine.

Coloration ( Fig. 5A )

In life, shield black, posterior shield gray; ocular acicles orange with broad black band at bases. Ocular peduncles black, with narrow orange band proximally and narrow white band close to cornea. Antennular peduncles black with distal half of terminal segments and flagella orange. Antennal peduncles, antennal acicles, and flagella orange. Chelipeds with meri and carpi black, bordered with orange on upper and anterior margins; chelae black with orange on upper margins of palms and dactyls, tip of dactyls pale orange to white, cutting edges of fingers white. Ambulatory legs uniformly black on meri, carpi and propodi. Dactyls black with bright orange rings varying as follows: with single, narrow ring distally ( Fig. 6A ), or with submedian and distal rings ( Fig. 6D ), or with distal orange ring and variably developed intermediate submedian ring ( Fig. 6B, C ). Abdomen tan with orange hues, sixth abdominal tergite and telson gray, white at margins, uropods white. In preservative, coloration of shield, ocular peduncles and chelae fading quickly to orange. However, coloration of ambulatory legs is still visible after 36 years in some specimens, and color pattern of dactyls is still visible after 100 years in the case of specimens collected during a cruise of the USFC Albatross ( USNM 40545).

REMARKS

Calcinus obscurus is closely allied, and easily confused with C. explorator . The differences between the two species are reported under the latter species. The easiest way to separate the two is by the armature of the ocular acicles, with two to four spines in C. obscurus instead of usually one spine in C. explorator . However, 3% of C. obscurus specimens examined have only one terminal spine on the ocular acicle, and thus this character should be used with caution to separate the two species. Coloration is overall black and very similar in C. obscurus and C. explorator , differing in minor details of the ocular peduncles, chelae, and dactyls of ambulatory legs (see Remarks under C. explorator ). The most obvious color difference is the presence of orange margins on chelae in C. obscurus only ( Figs 5A ; 3C ). The geographic distributions of the two are also different, with C. obscurus known from the mainland only from 13°29’N (La Libertad, El Salvador) to 4°07’S (Máncora, Peru), whereas C. explorator is insular (Cocos, Galápagos, Clipperton, Revillagigedo), and has been recorded at higher latitudes on the mainland between 25°55’N (Carmen I., Gulf of California) to 19°16’N (Tenacatita, Mexico).

Figures

FIG. 4. — Calcinus mclaughlinae n. sp., Clipperton: A, live specimen in shell; B, dorsal aspect; C, left chela, outer face; D, right chela, outer face; E, left P2 and P3, outer face; A, paratype, ovig. ♀ 2.0 mm (MNHN-Pg 7621); B-E, recently preserved holotype ♂ 4.4 mm (MNHN-Pg 7620). Scale bars: A, B, 5 mm; C-E, 2 mm.

FIG. 1. — Calcinus californiensis Bouvier, 1898, Acapulco (MNHN-Pg 7616): A, live specimen in shell; B, dorsal aspect; C, left chela, outer face; D, right chela, outer face; E, left P2 and P3, outer face; A, ♂ 4.5 mm; B-E, recently preserved ♂ 5.0 mm. Scale bars: A, B, 5 mm; C-E, 2 mm.

FIG. 3. — Calcinus explorator Boone, 1930, Clipperton (MNHN-Pg 7617): A, live specimen in shell; B, dorsal aspect; C, left chela, outer face; D, right chela, outer face; E, left P2 and P3, outer face; A, ♂ 2.4 mm; B-E, recently preserved ♂ 8.5 mm. Scale bars: A, C-E, 2 mm; B, 5 mm.

FIG. 5. — Calcinus obscurus Stimpson, 1859: A, live specimen removed from shell, dorsal view (photograph D. L. Felder); B-E, coloration strongly altered by preservative; B, left chela, outer face; C, right chela, outer face; D, left P2 and P3; E, propodi and dactyls of P2 and P3, showing alternate color pattern on dactyls; A, Panama, ♀ approximately 6.8 mm (ULLZ 5940); B-D, El Salvador, ♂ 6.2 mm (RMNH 9399); E, ibidem, ♂ 6.5 mm. Scale bars: A, 5 mm; B-E, 2 mm.

FIG. 6. — A-D, Calcinus obscurus Stimpson, 1859, variation of color pattern on P3 dactyl (coloration adapted from photographs): A, ♂ 7.5 mm,La Libertad,El Salvador (USNM 96289);B, ♂ 4.5 mm,Máncora,Peru (RMNH 14833);C, ♂ 6.4 mm,Taboguilla I., Panama (USNM 267556); D, ♂ 4.9 mm, Máncora, Peru (RMNH 14833); E, Calcinus tibicen (Herbst, 1791), outer face of P3 propodus, arrow indicates sulcus,?♂ 7.0 mm, coll. Mus. Antilles 1978, Guadeloupe (MNHN). Scale bars: A-D, 1 mm; E, 2 mm.