THE GBAPSOID CBABS OF AMERICA. 381 



The chief difference in the form of the male abdomen of the two 

 species lies in the penultimate segment : in monilifera it is less than 

 twice as wide as it is long; in maracoani just twice as wide as long. 



Measurements. Holotype male, length of carapace 28.7, width of 

 same at antero-lateral angles 45.4 mm. 



Range. West coast of Mexico. 



Material examined. 



Montague Island, mouth of Colorado River, Mexico; May 18, 

 1915 ; E. A. Preble, Biol. Survey, U. S. Dept. of Agriculture ; 1 male 

 (48829). 



Guaymas, Mexico; 1859; Capt. C. P. Stone, U. S. Navy; 1 male 

 holotype (1578, M. C. Z.), 1 male paratype (22180). 



UCA HETEROCHELOS (Lamarck). 



Plate 131, figs. 1 and 2. 



Cancer Vka una, DrasUicnsis SEBA, Thesaurus, vol. 3, 1758, p. 44, pi. 18, 



fig. 8 (inaccurate) ; Brazil. 

 Cancer vocans major HEUUST, Natur. Krabben u. Krebse, p. S3, 17S2, pi. 



1, fig. 11 (after Seba) ; Bahamas. 

 Ocypoda lictcrochclos LAMARCK, Syst. Anini. snns Vert., 1S01, p. 130 (no 



locality given; type in Paris Mus.?) ; refers to figures of Seba and 



Herbst. 

 Ocypoda iietcrochclos Bosc, Hist. Nat. Crust, vol. 1, an 10 [1801-1802], 



p. 197, " V Amcrlque meriilionale." 

 Cancer uka SHAW, Natur. Misc., vol. 14, 1802, pi. 588, colored (after Seba) 



and accompanying text (type-locality, Brazil) ; Cancer uca iu index. 



Not Cancer vca (uca) Linnaeus, 17G7. 

 Ocypodc hcterochclos OLIVIER, Eucyc. Meth., Insectes, vol. 8, 1811, p. 417 



(part). 



Uca una LEACH, Edin. Encyc., vol. 7, 1814, p. 430. 

 Gclasimus maracoani DESMAREST, Consid. Crust., 1825, p. 123 (part). 

 Gelasinnis platydactylits MILNK EUWAKDS, Hist. Nat. Crust., vol. 2, 1837, 



p. 51 (type-locality, Cayenne; type in Paris Mus.) ; Ann. Sci. Nat, 



ser. 3, Zool., vol. IS, 1852, p. 144 [108], pi. 3, figs. 2-26. 

 Gclasinnts grangcri DESBONNE, in Desbonne und Schrauim, Crust, de la 



Guadeloupe, 1SG7, p. 45 (type-locality, Guadeloupe, in the Canal; type 



probably not extant). 

 Gclasinnis hctcrochclcs KTNGSLEY, Proc. Acad. Nat. Sci. Philadelphia, 1SSO, 



p. 137, pi. 9, fig. 2 (part). 

 Uca platydactvla ORTJIANN, Zool. Jahrb., Syst, vol. 10, 1897, p. 346 (part). 



Diagnosis. Front very narrow, spatuliform. Movable finger of 

 large claw tapering. Fingers gaping throughout. Wrist and hand 

 granulate or finely tuberculate. 



Description. Allied to U. maracoani. Carapace wide, width of 

 male one and four-fifths times length. The raised line that bounds 

 the dorsal plane on each side is bent transversely inward at the pos- 

 terior end, and is more coarsely granulated in the female than in the 

 male ; the latter is true also of the dorsal surface. 



