166 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Measurements. Length of carapace, 45 mm. ; gastro-cardiac suture. 

 9.6 mm. 



Holotype. One male specimen, showing parts of the upper and 

 lower surfaces, but no appendages. The outer layer of the shell of 

 the carapace remains only in the central part, where the gastric, 

 branchial and cardiac regions meet. This surface is granulated and 

 areolated much as in Collinectes^ that is, the regions are separated 

 by definite depressions, the gastro-cardiac groove is transverse, there 

 is an areola at the inner angle of the branchial region, but there is a 

 shallower division into 2 lobules than in Callinectes. The post- 

 gastric area is incomplete anteriorly, so that it is impossible to tell 

 whether it is marked by a raised and granulated margin; the shape 

 of this area most nearly resembles that of G. exasperatus (Ger- 

 staecker 2 ), and its granulation that of C. bocourti A. Milne Edwards, 

 the granules being absent or sparse along the lateral and posterior 

 borders. Across the middle of the gastric region runs a blunt eleva- 

 tion, concave forward. The branchial region is divided in two by 

 a depression running obliquely backward and outward. These last 

 two features suggest the carapace of Euphylax dovii Stimpson, 8 a 

 species now existing on the Pacific coast of America, between Central 

 America and Payta, Peru. 



Anterior margin very broad, as in E. dovii, most of it being 

 occupied by the orbits; the front is narrow, T-shaped, much con- 

 stricted at base; the anterior part of the T has a concave surface 

 and is deflexed to meet the epistomial spine. This is more advanced 

 than the front; its tip is broken off. The upper margin of <he 

 orbit slopes backward and outward and is somewhat undulating. 

 The shape of the orbit can not be definitely made out, but a portion 

 of the smooth inner lining of the outer extremity remains. The 

 indications are that the eyestalk is long and the cornea! extremity 

 large, as in E. dovii. 



The sternum and abdomen resemble those of E. dovii, the anterior 

 end of the sternum is depressed, the depression having a Comdex 

 posterior margin, from which a furrow leads back to the abdomen. 

 Surface of sternum and abdomen covered with large and distant 

 punctae. Abdomen broadly triangular; first segment not dis- 

 tinguishable; second, third, and fourth segments each crossed by a 

 transverse ridge; third, fourth, and fifth fused, and perhaps also the 

 second with them. The sides of the penult segment are less con- 

 vergent than in E. dovii. 



This species in all the characters visible in the type-specimen re- 

 sembles the genus Euphylax as typified by E. dovii excepting in the 



1 Proc. U. S. Nat. Mus., vol. 18, 1896, pis. 12-23. 



2 Arch. f. Naturg., vol. 22, pt. 1, 1856, p. 129. 



3 Ann. Lye. Nat. Hist. N. Y., vol. 7, 1860, p. 226, pi. 5, fig. 5. 



