WEST AMERICAN CRUSTACEA. 575 



Suborder ANOMOURA. 



Family LITHODID/E. 



AcANTHOLiTHODEs gen, nov. 



Carapax lyrate, flattened, and covered with setose 

 spines. Rostrum rather prominent and terminated by 

 strong spines. The first basal joint of the antenna? has 

 one or more spines on the outer side ; the second basal 

 joint is produced forwards on the outer side into a long, 

 pointed process whose outer margin is armed with sev- 

 eral strong spines; there is a pointed, spiny, movable 

 acicle which is joined to the end of the second joint above 

 the base of the spiny process ; the third basal joint is 

 small and joined to the ventral side of the preceding one; 

 the fourth and fifth joints are subcylindrical. The isch- 

 ium of the third maxillipeds is widened, produced for- 

 ward at the antero-internal angle and dentate on the inner 

 margin; the last joints of the palp are not dilated. The 

 legs are covered with setose spines; chelipeds of mod- 

 erate size, more or less unequal, the fingers of one or 

 both hands excavated within and furnished with calcare- 

 ous teeth and corneous extremities. The first three pairs 

 of ambulatory legs are subequal. Abdomen soft, the 

 integument spiny; the first and the last two segments 

 strengthened with calcareous plates. Type A cantholithodes 

 hispid us (St.) 



This genus is founded on the species described as 

 Derniaturiis hispidus by Stimpson (in Ann. N. Y. Lye. 

 Nat. Hist. vol. vii, p. 242). It differs from Dermaturus 

 Brandt in the presence of spines on the body and legs, 

 and in the large, spiny, prolongation on the outer side of 

 the second joint of the antennas, which is entirely absent 

 in that genus. 



2d Ser., Vol. IV. ( 38 ) . March 20, 1895. 



