170 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



one-third the width of the carapace in the old, but is proportionally 

 narrower in the immature. In the old male, the first leg is nearly 

 twice as long as the carapace; the cheliped is stronger than the legs 

 and one and two-thirds times as long as the carapace; surface finely 

 granulate except on distal half of fingers; merus sub cylindrical, carpus 

 subspherical ; propodus a little compressed, increasing in width grad- 

 ually and regularly almost to the fingers where the lower margin bows 

 outward, giving the fixed finger a sinuous edge and making a consid- 

 erable gape between the proximal halves of the fingers, into which a 

 very low, broad tooth projects from the dactylus; meeting edges 

 crenulate. 



Color. — Brownish or buf? (Stimpson). 



Measurements. — Male (60021), length of carapace 20, width of same 

 18.8, fronto-orbital width 6, width of front 2.2, length of cheliped 34.4, 

 of first leg 39.4 mm. 



Range. — Cape San Lucas; ? Carmen Island. 



Material examined. — Cape San Lucas, Lower California, Mexico: 

 J. Xantus; 175 immature cotypes (2084); 12 males, 6 females, 

 cotypes (1242, M. C. Z.). March 23, 1911; Albatross; 1 male 

 (60021). A megalops (60065), thought to be this species, was taken on 

 southeast side of Carmen Island by the Albatross, 1911. 



Subfamily Acanthocyclinae 



C'yclinea or Cancroidea Corystidica {Acanthocyclidae) -\- Bellidea {Bellidae) Dana, 

 U. S. Expl. Exped., vol. 13, Crust., pt. 1, 1852, pp. 145, 294, and 403; pt. 2, 

 1853, pp. 1424 and 1428. 



Brachyura orbata Strahl, Monats. k. Pr. Akad. Wiss. Berlin, 1861 (1862) p. 717. 



Bellinae Bouvier, in A. Milne Edwards & Bouvier, Mem. Mus. Comp. Zool., vol. 

 47, 1923, p. 309. 



Outer antenna much reduced, with or without movable peduncle 

 and flagellum; the latter if present are insignificant; the first article 

 forms the anteruial gland, the second is dentiform, lies close to the 

 outer frontal tooth, and forms a boundary wall closing the inner end 

 of the orbit. Antennules strongly developed, unable to retract within 

 their basal cavity. Carapace subcircular or suboblong. Front ending 

 in a subtriangular point. Epistome very short, sunken. 



KEY TO THE GENERA OF THE SUBFAMILY ACANTHOCYCLINAE 



A'. Carapace broader than long. Antennae terminating at basal article. 



Acanthocyclus, p. 171. 

 A}. Carapace longer than broad. Antennae with two or more articles beyond the 

 basal article. 

 B'. Anterior half of carapace wider than posterior half. Pterygostomian 



region not advanced beyond line of front Corystoides, p. 173. 



B^. Anterior half of carapace not wider than posterior half. Pterygostomian 

 region advanced beyond line of front Bellia, p. 175. 



