34 BULLETIN 138, UNITED STATES NATIONAL MUSEUM 



Nob Hill (lumber yard), northeast of San Pedro; lower San 

 Pedro formation : 70 movable, 14 immovable fingers ; Cat. No. 353360, 

 U.S.N.M. 



San Pedro : two movable, two immovable fingers ; Cat. No. 353378, 

 U.S.N.M. 



Deadman Island, southeast of San Pedro; three movable, three 

 immovable fingers. 



The specimens enumerated above are probably in part H. nudus, 

 as they are much worn and difficult to determine. 



Range of Recent specimens. — From Prince William Sound, Alaska, 

 to Todos Santos Bay, Lower California. 



Family PINNOTHERIDAE de Haan 



Of small size. Carapace often more or less membranaceous, antero- 

 lateral margins entire or very slightly dentate. Front, orbits, and 

 eyestalks very small, corneae sometimes obsolescent. Buccal cavity 

 usually very wide, often semicircular. Merus of outer maxilliped 

 never quadrilateral, the palp never attached distinctly at antero- 

 internal angle ; ischium usually small, sometimes absent or fused with 

 merus. Interantennular septum a thin plate. Male abdomen very 

 narrow. Male openings sternal. 



Genus PINNIXA White 



CUVM CRABS 



Pinnixa White, Ann. Mag. Nat. Hist., vol. 18, 1846, p. 177; type, P. cylind- 

 rica White.— Rathbun, Bull. U. S. Nat. Mus., No. 97, 1918, p. 128. 



Carapace much wider than long; front narrow; orbit broadly 

 ovate or nearly circular, eyes small. Merus of outer maxilliped 

 large, ischium very small, palp large. Cheliped stout, palm com- 

 pressed. Third ambulatory \e^ longest, second next. 



Eocene; Recent. Not before found fossil. 



PINNIXA EOCENICA, new species 



Plate 1, figs. 3 and 4 



Description. — Carapace transversely oblong (pi. 1, fig. 3), broad- 

 est at the middle, the antero-lateral margins strongly arched, the 

 posterior margin slightly convex; surface very convex antero-pos- 

 teriorl}'-, almost level from side to side, hinder portion steep (pi. 1, 

 fig. 4). The groove separating the gastric from the hepatic and 

 branchial regions is broad and deep and is continued part way be- 

 side the cardiac region. Branchio-hepatic line little marked. Sur- 

 face except in the depressions finely granulate, the granules higher 

 and rougher on the posterior two-thirds of the branchial region. 



