242 Notes on North American Crustacea. 



like tliose of a comb, wliicli become more conspicuous outwardly as far 

 as the lateral lobes, wliere the margin becomes smooth. Ocular plates 

 or scales obliquely oblong, rather thick, broader behind ; antero-exterior 

 angle prominent, subacute ; inner angle rounded ; eye-specks obsolete 

 in most of our specimens, in others barely visible on the inferior side 

 of the ocular plate near the exterior angle. In other characters this 

 species approaches very near to L. scutellata. Length of carapax in a 

 female, 0.41 ; breadth, 0.47 inch. 



Cape St. Lucas. J. Xantus. 



LITHODOIDEA. 

 Dermaturiis hispid u§, no v. sp. 



Body depressed. Carapax moderately convex anteriorly, posteriorly 

 flattened, and even. A depression at the anterior extremity of the bran- 

 chial region. Cardiac transverse sulcus deep. Surface uniformly and 

 thickly covered with very small setose tubercles or short spines. Lateral 

 margins well defined but not at all projecting, and armed with spines a 

 little longer than the rest. The latero-inferior or epimeral surface may 

 be seen in a view from above, at the branchial regions. Eostrum rather 

 large, prominent, tumid, reaching to the tips of the eyes, with a tri-spinose 

 apex. Eye-peduncles hispid. In the external antennae both the acicle 

 and the process at its base are armed with three or four spines, flexible in 

 our specimen. The whole arrangement of the eyes and antennae shows 

 more similarity to the Lithodina than to the Hapalogastrina. External 

 maxillipeds of moderate size ; ischium projecting within with a denticu- 

 lated margin ; last two joints subcylindrical, not dilated. Feet thickly 

 beset with setose spines, longest on the margins, and more or less 

 clothed -jvith long hairs. Chelipeds not longer than the ambulatory 

 feet ; carpus and meros armed with two or three long spines within ; 

 fingers not gaping, and with cochleariform, black, corneous apices. 

 Ambulatory feet not flattened ; mi(^dle pairs one and two-thirds as long 

 as the carapax. Abdomen hispid like the carapax, but more minutely ; 

 plates of the basal joint broad ; right margin armed with a single close 



