558 BULLETIN 12CJ, UNITED STATES NATIONAL MUSEUM 



outer maxillipeds notched at inner angle. Chelipeds unequal, rather 

 short and heavy. Upper surfaces of arm and hand dilated toward 

 middle; margins irregularly denticulate. Fingers of larger cheliped 

 gape, those of smaller do not. Merus of last pair of feet barely 

 visible in a dorsal view. Third, fourth, and fifth segments of ab- 

 domen of male are fused; sixth segment has a sharp posterior, ap- 

 pressed spine, the tip of which lies between two tubercles on fifth 

 segment. 



Measurements. — Female (8485), length of carapace 14.5, width 21 

 mm. 



Habitat. — Dredged on shingly bottom. Bears a striking resem- 

 blance to a freshly broken chip or flake of stone, the sharply defined 

 edges of which are wonderfully imitated by the crab, even the claws 

 assisting, so much so as often to deceive the collector even when he 

 is on the alert, for he mistakes it for a small piece of broken pebble. 

 (P. W. Jarvis.) 



Range. — From Nantucket Sound, Massachusetts, to Georgia; 

 Gulf coast of Florida and West Indies as far as St. Thomas (A. 

 Milne Edwards). 



Material examined. — See table, pages 556-557. 



HETEROCRYPTA MACROBRACHU Stimpson 



Plate 203, figs. 3 and 4; plate 282, figs. 4 and 5 



Heterocrypta macrobrachia Stimpson, Ann. Lye. Nat. Hist. New York, vol. 

 10, 1871, p. 103 [130] (type-locality, Panama; type not extant). — A. 

 Milne Edwards, Crust. R^g. Mex., 1878, p. 167, pi. 29, figs. 3-36. 



Diagnosis. — Carapace one and one-fourth times as wide as long, 

 margins dentate. Postero-lateral margin between branchial ridge 

 and lateral angle deeply concave. Branchial ridges continued on 

 gastric region and terminating in two high, adjacent, gastric 

 tubercles. 



Description. — Carapace narrower and less triangular than that of 

 H. granulata, but resembling it in its granulated ridges and 

 protuberances. Antero-lateral margin regularly convex and crenu- 

 lated with 14 or 15 teeth which are themselves denticulated. Margin 

 between lateral angle of carapace and projecting terminus of branchial 

 ridge deeply concave. Posterior margins crenulated like the 

 anterior, with a somewhat larger tooth on each side at junction of 

 posterior with postero-lateral margins. Chelipeds very long, naked 

 and smooth except at crenulated edges. Legs compressed, carinated; 

 merus joints with sharp, minutely denticulated lower edge. A 

 blunt downward-pointing spine on sixth segment of male abdomen. 



Color. — Yellowish; sometimes with bluish-gray patches on the 

 carapace and bands of the same color across the chelipeds. 

 (Stimpson.) 



