410 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Toclos Santos Bay, Lower California: H. Hemphill; 4 males 

 (175TG). C. R. Orcutt; 25 specimens (19033). 



Santo Domingo, Lower California; Sept. 26, 1905; Nelson and 

 Goldman; 15 males (33415). 



Mangrove Island, Magdalena Bay, Lower California; Mar. 20, 

 1911; Albatross ;2 males (44580). 



La Paz, Gulf of California; L. Belding; 34 males, G females (types 

 of Gelasimus gracilis Rathbun) (4022). 



Pichilinque Bay, Gulf of California; Apr. 29, 1888; Albatross; 23 

 males, 7 females (22080). 



San Luis Gonzales Bay, Gulf of California; Mar. 27, 1889; Alba- 

 tross; 4 males (17458). 



San Felipe Bay, Gulf of California; June 23, 1905; Nelson and 

 Goldman; 13 males, 1 female (32630). 



Lower California; M. Diguet; 1 male, 1 female (20301). 



Guaymas, Mexico; Capt C. P. Stone; 13 males, 3 females (M. C. %.). 



Mazatlan, Mexico; H. Edwards; received from Peabody Acad. 

 Sci., Salem; 1 female y. (M. C. Z.). 



UCA COLORADENSIS (Rathbnn). 



Plate 147. 



Gcla aim-us colorndcnsis RATHRUN, Proc. U. S. Nat. Mus., vol. 1C, 1893, p. 



24G (type-locality, Horseshoe Beud, Colorado River; male holotype, 



Cat. No. 174f)9, U.S.N.M.). 

 TJca r.oloradensis HOLMES, Occas. Papers California Acad. Scl., vol. 7, 1900, 



p. 76. 



Diagnosis. Oblique ridge inside palm continued to upper mar- 

 gin. Upper surface of palm at right angles to outer surface. Lat- 

 eral margins of carapace angled. 



Description. Allied to the two preceding. Carapace widest be- 

 hind the antero-lateral angles, the side margins beifig straight ante- 

 riorly, then turning abruptly inward at the widest point. Dorsal 

 sulci very deep; a long groove with lateral branches on the branchial 

 region. Front one-fourth the extreme width of the carapace. 



The outer surface of the palm is abruptly bent over above, form- 

 ing an almost horizontal upper surface; granulation coarse along 

 the bend. Fingers about twice as long as palm. 



Oblique tuberculate ridge on inner surface of palm bent at a right 

 angle at the middle. 



Otherwise much as in U. crenulata. 



Measurements. Male (17459), length of carapace 12.5; width of 

 same 20 mm. 



Range. Mexico : Head of Gulf of California ; Guaymas. 



