138 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



which are small, blunt or subtrimcate. Orbit wdth two teeth above 

 beside those at the extremities, one between the sinuses narrower 

 than in crihrarius, the other small but well developed and lying further 

 inward, close to the sinus. Antero-lateral teeth longer and narrower 

 than in crihrarius, seventh and eighth teeth of subequal width, eighth 

 considerably longer. 



Three spines on anterior border of merus, one tooth at distal end 

 just above posterior border. The outermost of the carpal spines is the 

 smallest. Both superior carinae of the manus terminate in a spine, 

 the outer the smaller. The merus of the swimming foot is a little 

 longer in proportion to width than in crihrarnus. 



Color. — The color pattern of the carapace is similar to that of the 

 preceding species but the light spots are less uniformly round. The 

 spotting of the chelipeds is very much reduced or altogether absent. 



Measurements. — Male (60975), total length of carapace 40, width of 

 same 91, width at anterior base of lateral spine 70, fronto-orbital 

 width 28.8, width of front (two teeth) 5 mm. 



Range. — Lower California, Mexico, to Peru. 



Material examined. — 



MEXICO.— Lower California: Ballenas Bay; March 16, 1911; 

 Albatross; 1 male, 1 female (60003). Magdalena Bay; San Diego 

 Society of Natural History; 1 male (returned to sender). Carmen 

 Island, Gulf of California; 1889; Albatross; 1 young (17448). 



NICARAGUA —Corin to : J. A. McNiel; 2 males, co types of 

 A. bidens (5315, M.C.Z.). C. F. Baker; male (29316). 



PANAMA.— Cocos Island, off Bay of Panama; Feb. 28, 1891; 

 Albatross; 3 males (20607). Taboga Island, Bay of Panama; May 

 11-15, 1911; Meek and Hildebrand; 1 male (Field Mus.), 1 male, 

 1 female (44203); received from Smithsonian B'ological Survey. 



PERU. — Salavery; October 21, 1926; collected from surf by men 

 and boys for W. L. Schmitt; 11 males, 56 females (60975). Ancon; 

 sand beach; February 13; R. E. Coker; 1 male (40441); received 

 from Peruvian Government. 



Genus CRONIUS Stimpson 



Cronius Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1860, p. 225 [97]; 

 type, C. ruber (Lamarck). 



Charybdella Rathbun, Proc. Biol. Soc. Washington, vol. 11, 1897, p. 166; sub- 

 stituted for Cronius, preoccupied, according to a rule then valid, by Cronia 

 H. and A. Adams, 1858; Bull. U. S. Fish Comm. for 1900, vol. 2, 1901, p. 51. 



Al ied to Portunus, differing chiefly in the orbit more nearly circular, 

 the basal lobe of the antenna prolonged into the orbital hiatus and the 

 flagellum more remote from the orbital cavity. Carapace narrow; 



