406 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



lower edge close to upper but distinct. Postorbital angle prominent, 

 acute, and directed obliquely outward. Lateral margins strongly 

 convergent, the lower margins straight, but the upper margins, or 

 those which bound the dorsal plane, are slightly sinuous and are pro- 

 longed almost to the posterior margin. 



Merus of larger cheliped of male slightly rugose; carpus lightly 

 granulated; hand similar to that of IJ . crenulata; outer surface of 

 palm finely granulated and lower edge margined ; an oblique, granu- 



I'lG. ICS. \\l\ RECTILATUS, COTYPE, ENLABGED, AFTER HOLMES. 0, DORSAL VIEW OIT 



CARATACE, EVES, AND LEOS ; 5, ISCHIUM AND MEIEUS CF RICHT OUTER MAXILLII'ED; 

 C, CAItl'US AND CHEL\ OF SMALLER CHELU'EO; d, MERCS OF RIGHT OB LARGER CBELIPED, 

 INNER face; e, LARGER CUELA, INNER FACE. 



lated ridge on inner surface, beginning at lower margin and ending 

 at carpal groove. Pollex tapering, a tooth near the middle, extremity 

 slightly excavated; dactyl curved more strongly toward the tip, 

 which slightly overreaches the pollex. Ambulatory legs slender. 

 (Abridged from Holmes.) 



MeasureTRenU. — Male, type, length of carapace 8.75, width of same 

 13.5 mm. 



Range. — West coast of Lower California. Known only from the 

 type specimens, which were destroyed in the San Francisco fire. 



UCA THAYERI Rathbon. 



Plate 144. 



Ciccie Etc Marcgrave de Liehstad, Hist. Rer. Natur. Brazil, 1G48. p. 185, 



text fiff.; Brazil. 

 Uca ihaycri RATHnuN, Proc. Washington Acnd. Scl., vol. 2, 1900, p. 134, 



pi. 8, fi?fs. 1 and 2 (type-locality. Rio Paraliyb;) do Norte at Cabedello; 



type, Cat. No. 23753, U.S.N.M.). 



Diagnosis. — Front narrow. Sides strongly convergent. Oblique 

 ridge inside palm not ending at carpal cavity but continued partly 

 upward. 



Description. — Carapace strongly narrowed behind, Avidest either at 

 the lateral angles or a little farther back; sides sinuous. Inter- 

 regional depressions deep ; surface finely granulose and tomentose. 



