422 BULLETIN 152, tJNITED STATES NATIONAL MUSEUM 



^nterdigital sinus. On major dactyl a strong basal tooth and a large 

 tooth at distal third, projecting into the gape. Fingers hooked at 

 tips, not gaping in minor chela. 



Color. — Very dark bluish gray, marbled posteriorly; fingers black 

 with light tips. (Stimpson). 



Measurements. — Male (50966), length of carapace 8.4, width of 

 same 13.4, fronto-orbital with 7.8, width of front 4 mm. 



Range. — West coast of Mexico. 



Material examined. — 



WEST COAST OF GULF OF CALIFORNIA.— Agua Verde Bay; 

 April 1, \^l\; Albatross; 1 male (50966). 



San Francisquito Bay; beach; April 9, 1911; Albatross; 4 males 

 (Amer. Mus.). 



La Paz: L. Belding; 2 males, 2 females (4629). La Paz Harbor; 

 March 12, 1889; Albatross; 1 female (16025). 



Cape San Lucas; John Xantus; 2 males, 4 females (1 ovigerous), 

 cotypes (1253, M. C. Z.). 



BELOW GULF OF CALIFORNIA.— Maria Madre Island; March- 

 May, 1927; from Secretaria de Agricultura y Fomento, through 'A. L. 

 Herrera; 1 ovigerous female (60733). 



Genus EURYTIUM Stimpson 



Eunjtium Stimpson, Aun. Lye. Nat. Hist. New York, vol. 7, 1859, p. 56 [10]; 

 type, E. limosum (Say). 



Carapace very broad, convex, regions slightly marked, without 

 transverse raised lines. Antero-lateral borders regularly arcuate, 

 shorter than posterolateral, cut into five shallow teeth, the second 

 tooth rounded and intimately fused with first. Fronto-orbital 

 border half or a little more than half the width of carapace. Front 

 from a fourth to almost a third the width of carapace. Front de- 

 flexed, two rounded lobes separated by a V-shaped notch. Superior 

 margin of orbit with two short and inconspicuous fissures; lower 

 margin with a deep rounded sinus outside, and two unequal lobes. 

 Basal antennal segment broad and in contact with front; the flagellum 

 stands in the orbital hiatus. The ridge on the endostome which 

 defines the efferent branchial channel is well marked, and continues 

 to margin of epistome. Chelipeds massive and rounded, unequal in 

 both sexes. Abdomen in male with third to fifth segments fused. 



Related to Panopeus and its allies, but distinguished by its oval 

 and almost smooth carapace, without ridges, and by its strong palatal 

 ridge. 



Along the Atlantic coast of America from New York to the State of 

 Sao Paulo, Brazil; on the Pacific coast from Mexico to Peru. Ber- 

 mudas. 



