310 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



besides the postorbital, the largest spine at the lateral angle. Tuber- 

 cles of carapace prominent, each culminating in a single spine; a 

 tubercle with spine on posterior angle. 



Chelipeds slender, about same length as next pair of legs; merus 

 with 4 tubercles above; manus smooth, slender; fingers small, slender, 

 in contact most of their length, serrate on inner border. Ambulatory 

 legs slender, rounded, first pair much the largest; dactyli sharp 

 (Lockington) , 



Measurements. — Male cotype, length of carapace 20, width 12 mm.; 

 female cotype, length of carapace 23, width 15 mm. 



Material examined. — None. 



Range. — Gulf of California; known only from the description of 

 the three type-specimens. 



Remarlcs. — Perhaps the same as Lihinia mexicana. 



Genus LIBINIA Leach 



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

 Leach. — Rathbun, Proc. U. S. Nat. Mus., vol. 15, 1892, p. 235 (part: not 

 L. macdonaldi and spinimana) , and synonymy. 



Carapace convex; tuberculous or spinous; triangular-orbiculate 

 and evenly rounded behind the frontal region. Preocular spine 

 usually distinct. Rostrum emarginate or bifid at the apex. Orbits 

 small, nearly circular, with a superior fissure closed or nearly so, and 

 a closed fissure or an open sinus below. Basal antennal segment 

 moderately enlarged. Merus of external maxillipeds truncate at 

 distal end. Chelipeds well developed; palm elongate; fingers with 

 one exception evenly denticulate on inner margins. Ambulatory 

 legs well developed, sometimes elongate, diminishing in length from 

 first to fourth pair; segments subcylindrical, usually unarmed. 



America, from Nova Scotia to Terra del Fuego, and from Lower 

 California, Mexico, to Chile; San Francisco, California. Bermuda?; 

 West Africa. 



KEY TO THE SPECIES OF THE GENUS LIBINIA 



A'. Merus of chelipeds unarmed or bearing only one spine or tubercle. 

 B'. Rostrum either horizontal or defiexed. 

 C Median spines more than 6. 



D'. Tubercles of carapace numerous, nongranulate, more or less unevenly 

 placed. Median tubercles or spines 9, 5 behind cervical groove. 

 Tooth or tubercle at angle of basal segment of antenna incon- 

 spicuous from above emarginata, p. 311. 



D^. Tubercles and spines of carapace not numerous, granulate, evenly 

 placed. Median tubercles or spines 7, 4 behind cervical groove. 

 Tooth or spine at angle of basal segment of antenna curved, con- 

 spicuous from above spinosa, p. 325. 



C^. Median spines 6. 



D'. No spine at middle of hepatic region. 



E'. Fork of rostrum in adult shallow, tips of horns blunt. Lateral mar- 

 ginal spines in young of good size, subequal _dubia, p. 313. 



