26 BULLETIN 138, UNITED STATES NATIONAL MUSEUM 



groove on either side, the outer groove wider than the inner, surface 

 coarsely punctate, a large tooth in the gape ; on the other hand, the 

 grooves are deeper than in longlpes^ the finger shorter in proportion 

 to its basal width and slightly more curved ; moreover, the dentation 

 of the distal half is not true to type. It consists of five teeth, 

 diminishing in size, the proximal one being larger than the subbasal 

 tooth, the space between the two having at its middle a small tooth 

 or tubercle ; in Imigijjes the distal teeth are seven or eight in number, 

 are more closel}^ placed and similar in shape and size, becoming 

 smaller gradually toward tip of finger. 



Occurrence.- — Deadman Island, southeast of San Pedro; Pleisto- 

 cene series; one right movable finger. 



Genus LIBINIA Leach 



Lihinia Leach, Zool. Misc., vol. 2, 1815, p. 129 ; type, L. emarginata Leach, 

 Recent.— Rathbun, Bull. U. S. Nat. Mus., No. 129, 1925, p. 310. 



Carapace rotund, tuberculate or spinous, with a small, emarginate 

 rostrum. Orbits small, subcircular, upper fissure closed or nearly 

 so. Palm elongate, fingers usually evenly denticulate on prehensile 

 edges. Miocene; Pleistocene; Recent. 



LIBINIA SETOSA Lockington 



LiMnia setosa Lockington, Proc. Calif oruia Acad. Sci., vol. 7, 1876 (1877), 

 p. 68 [6].— Rathbun, Bull. U. S. Nat. Mus., No. 129, 1925, p. 327, pi. 

 243. 



Occu7Tence. — California ; Pleistocene : 



Rincon del Potrero, Santa Monica ; one large movable finger ; Cat. 

 No. 353364, U.S.N.M. 



Spanish Bight, San Diego Bay; one large movable finger, 



Bangs of Recent specimens. — Known only from the west coast of 

 Lower California. 



Family PARTHENOPIDAE Alcock 



Chelipeds not especially mobile, usually much longer and heavier 

 than the other legs and with fingers bent on hand at an angle toward 

 the side on which the fixed finger is set. Second article of antennae 

 small, short, not fused with epistome or front. Orbits well made. 

 Hooked hairs almost ahvays Avanting. Palp of external maxillipeds 

 articulated at antero-internal angle of merus. 



Genus MESORHOEA Stimpson 



Mesorhoea Stimpson, Bull. Mus. Comp. Zool., vol. 2, 1871, p. 135 ; type, 

 M. sexspinosa Stimpson. — Rathbun, Bull. U. S. Nat. Mus., No. 129, 

 1925, p. 546. 



Carapace pentagonal, smooth, convex, bearing four large spines, 

 on the gastric, cardiac and branchial (paired) regions. Efferent 



