160 



BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Description of male. Carapace smooth, punctate, punctae small 

 and scarce in middle third, large and more numerous elsewhere. A 

 deep groove separates anterior cardiac region from gastric and bran- 

 chial regions; a sharp, granulate antero-lateral crest which does not 

 reach cervical suture; a transverse ridge crosses middle of cardiac 

 region between bases of feet of last pair; outer angles hairy; poste- 

 rior border short, a little concave. Front not prominent, truncate, 

 with a submarginal groove, produced backward at middle. 



Chelipeds smooth, punctate ; chelae suboval ; fingers horizontal, of 

 subequal length, tips strongly hooked and overlapping when closed, 

 leaving a gape; a sharp, finely milled crest runs from tip of pollex 

 backward and upward, about two-fifths length of palm; a tooth on 



dactylus near mid- 

 dle of prehensile 

 edge, one on pol- 

 lex distal to the 

 middle. 



Dactyli of legs 

 straight in the 

 main, the fourth 

 one convex poste- 

 riorly and slightly 

 concave anteriorly. 

 First leg slender, 

 reaching to end 

 of propodus of 



FIG. 99. PINNIXA CYLINDKICA, MALE (17952). a, OciEtt MAX- second; SCCOnd 



ILLII'ED, X 19 ; 6, ABDOMEN, X 7|. j -,1 



stouter, to middle 



of dactylus of third; third very stout, merus 1 times as long as 

 wide, distally narrowed, upper and lower margins finely granulate; 

 fourth leg very short, reaching beyond merus of third by half length 

 of dactylus. 



Color. Yellowish grey (Stimpson). 



Measurements. Male (17952), length of carapace 5.8, width of 

 same 11.8 mm. Female (49126), length of carapace 7.8, width of 

 same 15.3 mm. 



Habitat. "Lives with the lobworm (Arenicola cristata} in its 

 hole in the sand, which is not lined by any tube. The young occur 

 in the early spring on slimy shores at low-water mark" (Stimpson). 



Range. North Falmouth, Massachusetts ; Chesapeake Bay to Sar- 

 asota Bay, Florida. 



Material examined. 



North Falmouth, Massachusetts; Aug. 5, 1914; F. M. Root; 1 

 female (4912G). 



