THE CANCROID C RABS OF AMERICA 385 



lower angle of orbit conical, produced much beyond upper angle; 

 outer hiatus deep, closed at bottom, wide spreading at opening. 

 No subhepatic tubercle. 



One and sometimes two small teeth on upper margin of arm; carpal 

 groove deep, tooth at inner angle subcylindrical, stout, obtuse, a 

 shallow lobe below it; major palm smooth, deep, swollen, fingers 

 widely gaping, a cylindrical tooth near the base of the strongly arched 

 dactyl; fingers hooked at tips; the color of immovable finger ends in 

 the old, in an oblique line not extending further on palm; in smaller 

 specimens the color line is vertical and does not quite reach base of 

 finger. Legs slender; dactyls long and hairy. 



Third, fourth, and fifth segments of male abdomen partially anchy- 

 losed; third segment not as wide as first, its 

 outer ends rounded; terminal segment rounded 

 at tip. 



Color. — Variable, sometimes a uniform brownish 

 yellow or even light buff, but usually a dark red- 

 dish brown or dark gray, the females usually 

 darker than the males and often more or less 

 spotted. In both sexes the fingers are black or 

 dark brown at the base, lighter at the tips. (Hay 

 and Shore.) 



M.«m«menfe.-Male holotype, length of cara- ^Z^S^^X^J^iTSZ 

 pace 17.8, width of same 26.5, fronto-orbital men, enlarged, after 

 width 13, width of front 7.2 mm. Most of the ^^^^^'"" ^^° ^^^^^'^ 

 specimens from Chesapeake Bay and from South Carolina southward 

 are small. 



Variation. — A single male (21236) from Jamaica is atypical. 

 It has the not uncommon abnormalitJy of two minor chelipeds instead 

 of a major and a minor; but these are not only similar in form but of 

 nearly equal size and are much longer and stronger than its small 

 carapace (11.6 mm. wide) would normally carry, the merus projecting 

 well beyond the carapace. In addition, the sinus of the coalesced 

 lateral tooth of the carapace is deeper and wider than usual and the 

 ambulatory legs are very narrow, the merus of the last pair being 4.6 

 by 1.1 mm.; the size of the corresponding member of a male of 13.5 

 mm. carapace-width (15643) is 4.5 by 1.4 mm. 



Range. — From Massachusetts (Vineyard Sound) to Gulf of Mexico 

 (Louisiana), Bahamas and Jamaica. 



Material examined. — See table, pages 386 to 392. 

 79856—30 26 



