84 BULLETIM 138, UNITED STATES NATIONAL MUSEUM 



Genus HEPATUS Latreille 



Eepatus Latreille, Hist. Nat. Crust., vol. 3, 1801-1802, p. 22; type, n. 

 princeps ( Herbst ) . 



Carapace broad, convex, regularly arcuate in front, strongly nar- 

 rowed behind; hepatic regions very large, branchial very small. 

 Front narrow, straight, rather prominent; orbits small, circular; 

 antero-lateral margin prolonged beneath the orbits to join margin 

 of buccal cavity. Chelipeds strong, when flexed fit closely against 

 lower surface of body. Hands with a superior crest, fingers inclined 

 downward and inward. Abdomen of seven segments. 



Oligocene; Pleistocene; Recent. 



HEPATUS LINEATUS Rathbun 



Hepatus Uneatus Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, p. 610, pi. 

 44, fig. 4. 



Occurrence. — California ; Pleistocene : 



Signal Hill (or Los Cerritos), north of Long Beach: one large 

 dactylus of right cheliped ; Cat. No. 353361, U.S.N.M. 



Spanish Bight, San Diego Bay; one small dactylus of right chel- 

 iped ; Cat. No. 353362, U.S.N.M. 



These fingers are distinguished at once from others found at the 

 j-ame localities by the longitudinal, finely milled, stridulating ridge 

 on the inner surface, a little below the upper edge and running the 

 whole length of the finger except on the horny tip. 



Range. — This Recent species has never been taken on the Cali- 

 fornia coast but only off Abreojos Point and in Magdalena Bay, 

 Lower California. 



Genus NECROCARCINUS Bell 



Xecrocarclnus Bell, Monog. Fossil Malac. Crust. Great Britain, 1862 (1863), 

 p. 10: type, X. bcchei (Deslongchamps). 



Carapace suborbicular, furnished Avith large tubercles arranged in 

 regular lines, antero-lateral margin arcuate, dentate, front triangular. 

 Orbits round, with a dorsal and forward aspect, bifissured above. 

 Hand high, fingers shorter. 



Cretaceous; Eocene. 



NECROCARCINUS HANNAE. new species 

 Plate 18. figs. 1 and 2 



Description. — Surface covered with minute, crowded pimctae, in- 

 visible to the naked qjq. A broad furrow divides the median regions 

 from the lateral regions; alongside the gastric region the furrow is 

 deep, but at the cardiac region it becomes shallow and disappears 

 altogether before reaching the posterior margin. The clivision be- 

 tween the hepatic and branchial regions is sluiUow, not well defined. 



