486 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



Habitat. — Fairly common on shelly bottoms and not infrequently 

 crawling over wharf piles. (Hay and Shore.) 



Range. — North and South Carolina, west and southwest coast of 

 Florida, Bahamas, Jamaica, Guadeloupe (A. Milne Edwards), 

 Curasao. 



Material examined. — See table, pages 487-490. 



PILUMNUS XANTUSn Stimpson 



Plate 201, Figures 1-3 

 Pihimnus xantusii Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1860, p. 

 213 [85] (type-locality. Cape St. Lucas; cotypes in Paris Mus. and M.C.Z., 

 Cat. No. 1259). — A. Milne Edwards, Crust. R^g. Mex., 1880, p. 284, pi. 51, 

 figs. 1-16. 



Diagnosis. — Five lateral marginal spines. Superior margin of 

 orbit unarmed. Ambulatory legs without spines. Carapace less 

 than a fifth wider than long. ^ 



Description. — Carapace narrow, moderately convex, anteriorly hairy 

 but posteriorly short-pubescent like the abdomen. Gastric region 

 and its principal lobules well circumscribed. Several very shert 

 spines on the hepatic and branchial regions toward the antero-lateral 

 margin. Surface elsewhere either smooth or sparsely roughened 

 with sharp grains. Front rather broad, arcuate, deeply incised at 

 middle but without lateral incisions; margin armed with six or more 

 small spines. Superior margin of orbit straight, ciliated, but not 

 armed with spines; inferior margin spinulous and vnth two or three 

 spines toward inner angle. Antero-lateral margin armed with five 

 spines, regularly placed and nearly equidistant, but diminishing in 

 size forward; the anterior one at external angle of orbit. 



Merus of outer maxillipeds longer than usual in the genus, being 

 nearly square, and less incised at the internal angle. Chelipeds 

 short and thick; greater hand hairy above and externally and armed 

 with spines; surface between the spines smooth and glabrous except 

 toward the fingers where it becomes granulated, the spines disappear- 

 ing or becoming tubercles; lower surface and inner side near fingers 

 granulated. Fingers tuberculate at base. Ambulatory legs not 

 spinous but clothed above with very stiff hairs. 



Color. — Reddish; spines black; fingers black. 



Measurements. — Male type, length of carapace 15.2 mm. (0.6 inch), 

 width of same, spines excluded, 17.3 mm. (.68 inch). (Stimpson.) 

 Length of largest male examined 11.7, A\ddth without spines 14, 

 width of front 4.6 mm. 



Range. — Cape St. Lucas, Lower California, Mexico. Known only 

 from the type-locality. 



Material examined. — Cape St. Lucas; John Xantus; 1 male, 1 female, 

 cotypes (62737); cotypes (1259, M.C.Z.). 



