158 



BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Diagnosis. A sharp carina runs on the dorsum from antero- 

 lateral margin across cervical suture. A single, bilobed, cardiac 

 carina. Dactyli of legs slender ; posterior margin of last pair convex. 

 Description of male. Allied to chaetopterana. Much less hairy. 

 A sharp denticulated carina extends from base of third leg across 

 branchial region and across cervical suture to hepatic region. A 

 sharp bilobed carina on cardiac region. Fixed finger of chela more 

 deflexed than in chaetopterana^ its basal tooth weaker ; dactylus more 

 strongly curved. Legs long and slender; first leg reaches to end of 

 propodus of second, second and third same length, fourth reaching 

 beyond middle of carpus of third ; merus of third leg about 3i times 



as long as wide, its 

 lower margin as well 

 as that of the propo- 

 dus minutely denticu- 

 late; dactyli of first 

 two legs slightly 

 curved, of last two 

 straight ; anterior 

 edge of dactylus of 

 last leg straight, pos- 

 terior edge convex. 

 Abdomen wider, sides 

 chiefly convex. 



Sexual variation. 

 Cardiac carina less 

 raised and less sharp 

 in female than in 

 male. Fingers not 

 gaping ; thumb longer, 

 less deflexed, acutely pointed, widened at middle ; dactylus less verti- 

 cal than in male. 



Color. A rather fresh specimen is covered with very fine brown- 

 ish dots, denser above than below. 



Measurements. Male (18211), length of carapace 4.8, width of 

 same 9.7 mm. Female (18806), length of carapace 3.5, width of 

 same 7 mm. 



Development. From the zoea direct to the crab form. 

 Habitat. Either found free or dug out of the mud. In stomach 

 of ocellated flounder (Verrill). 



Range. Vineyard Sound, Massachusetts, to Sarasota Bay, Florida. 

 Shore to 26 fathoms. 

 Material examined. 



Vineyard Sound, Massachusetts; 1871; Verrill, Smith and Todd, 

 U. S. Fish Comm.; 1 female (18806). 



4 



a b 



FlO. 98. PlNNIXA SATANA, MALE (18211). C, OOTEB MAX- 



ILLll'ED, X 20 J &, ABDOMEN, X 11 j. 



