158 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



thin, oblong, sides parallel to near the tip, where they are thick, re- 

 curved and convergent; tip bilobed, lobes small, sinus wide. Cheliped 

 of young male shorter than first leg, fingers not gaping. 



First and second legs (others missing) similar, stout, merus lami- 

 nate above, and two or three toothed, the tooth at distal end prom- 

 inent, upstanding; propodus with a strong tooth below, at proximal 

 end, similar to that in E. hrasiliensis. 



Measurements.— Male, holotype, length of carapace 4.8, greatest 

 width 3.5 mm. 



Range. — Known only from the type-locality. 



Material examined. — Chincha Islands, Peru; November 30 to 

 December 1, 1919; Robert Cushman • Murphy, collector; 1 male, 

 holotype (54208) ; received from the Brooklyn Museum. 



EPIALTUS CRENXn^ATUS Rathbun 



Epialtus crenulatus Rathbun, Proc. Biol. Soc. Washington, vol. 36, 1923, 

 p. 71 (type-locality, Lower California; holotype, 1 ovigerous female; 

 Cat. No. 18135, U.S.N.M.). 



Diagnosis. — An Epialtus with large hepatic lobe, small, acute, 

 branchial lobe, oblong, entire rostrum, and no tooth on propodites 

 of legs. 



Description. — The hepatic lobe is not advanced, the anterior margin 

 transverse and forming with the outer margin a rounded lobe with 

 crenulated edge. The rostrum is about as broad as long, sides arcuate 

 for the most part, extremity truncate, with a faint indication of 

 emargination; below there is a median furrow with a crest on either 

 side. Preorbital tooth large, not projecting. Hepatic and branchial 

 widths of carapace equal (fig. 53,/). 



Cheliped of female short, palm short and stout. The first ambu- 

 latory is longer than the cheliped and noticeably longer than the 

 other legs; propodites of last three provided with a tuft of hair at 

 proximal end of lower margin. 



Measurements. — Female, holotype, length of carapace 6.4, width 

 5 mm. 



Range.— Known only from the type-specimen. 



Genus MOCOSOA Stimpson 



Mocosoa Stimpson, Bull. Mus. Comp. Zool., vol. 2, 1871, p. 128; type, M. 

 crebripunctata Stimpson. — A. Milne Edwards, Crust. R6g. Mex., 1878, 

 p. 137. 



Carapace subpentagonal, tumid; rostrum subtriangular, obtuse, 

 excavated below. Eyes large, immovable, filling the orbit. External 

 antennae concealed beneath the rostrum and not reaching to its tip; 

 basal article triangular, unarmed. External maxillipeds very broad, 

 closing the buccal cavity; merus particularly short and broad, quad- 

 rate, with the outer angle much projecting outward, and the inner 



