Calcinus obscurus Stimpson, 1859
Illustrations. - Calcinus obscurus Stimpson, 1859. After Holthuis (1954: 21, fig. 5). Calcinus obscurus Stimpson, 1859. - Chelae and left third P3. After Holthuis (1954: 22, fig. 6).
References. - Calcinus obscurus Stimpson, 1859: 83 (not seen).
Calcinus obscurus - Holthuis, 1954: 20, fig. 56 (lagoon near La Libertad, Salvador, central America). - Hendrick & Harvey, 1999: 368 (additional references and distribution: La Libertad, El Salvador, to Ecuador, to ?California). - Boschi, 2000: 71 (Checklist; Panamic province).
Shield and cephalic appendages. - Ocular scale with several terminal spines (34 spines on left and 23 on right). Species of normal size, i.e. shield length often greater than 23 mm.
Chelipeds (P1). - Upper margin of right chela smooth. Outer face of left palm regularly convex.
Ambulatory legs (P2-P3). - Dorsolateral margins of P3 propodi slightly carinated. Distal pilosity of P3 weak, similar to distal P2.
Armament of telson. - Left lobe of telson with a single spine. Right lobe with a single spine.
Coloration. - Ocular peduncle multicolored with narrow ring close to cornea. Chela uniformly colored, often grading to paler distally. Ambulatory legs (P2 & P3) with ring(s) (median ring on dactyls).
Habitat. - Intertidal rocky shores.
Geographic distribution. - La Libertad, El Salvador, to Ecuador, to ?California. East Pacific.
Remarks. - Specimens examined in MNHN collection (J. Poupin): 'Côte Ouest de l'Amérique du Sud', 1 male 9.2 mm, 3 females 5.67.0 mm, G. Nobili det. 1905 (MNHN Pg 805); Panama, 1 male 8.6 mm (Pg 802), 1 male 6.0 mm, 1 female 7.0 mm (Pg 803).