I8OPODS OF NORTH AMERICA. 37 



Family II. APSEUDID^E. 



Body attenuated behind. First pair of antennae with two unequal 

 multiarticulate flagella. Second pair of antennae usually furnished with 

 a scale at the end of the second article of the peduncle. Mandibles with 

 palp. Anterior maxillae with two masticatoiy lobes. Posterior max- 

 illje well developed and setose. Epignath of maxillipeds large, lam- 

 inar, branchial in character. Two anterior pairs of legs, usually 

 provided at the base with minute, two-jointed exopods (exopodites). 

 Second pair of legs fossorial in character. Uropoda double-branched; 

 branches multiarticulate. 



ANALYTICAL KEY TO THE GENERA OF APSEUDID^E. 



a. Second pair of antennae with a scale articulated to the end of the second article. 



Head and first thoracic segment coalesced. 

 b. Exopods present on both pairs of gnathopods. 



c. Five pairs of pleopoda present, with branches uniarticulate. Abdomen com- 

 posed of six segments Genus Apseudes Leach 



c/. Only four pairs of pleopoda present, with one of the branches two-jointed. 



Abdomen composed of six segments Genus Parapseudes Sars 



b' '. Exopods absent on both pairs of gnathopods. Five pairs of pleopods present, 

 in which one of the branches is two-jointed. Eyes absent. 



Genus Typhlapseudes Beddard 



a'. Second pair of antennae without a scale. Head and first two thoracic segments 

 coalesced. Eyes absent Genus Sphyrapus Norman and Stebbing 



8. Genus APSEUDES Leach. 



Second antennae with a scale articulated to the end of the second 

 article. Exopods present on both pairs of gnathopods. Five pairs 

 of pleopoda present, in which the branches are uniarticulate. First 

 pair of legs in male larger than in female. First pair of antennae 

 usually alike in the two sexes. 



ANALYTICAL KEY TO THE SPECIES OF THE GENUS APSEUDES. 



a. Head with rostrum short, produced to a mere point. Body without spiny arma- 

 ture. Flagellum of first antenna of same length as secondary filament. 



Apseudes espinosus Moore 

 a'. Head with distinct rostrum. Body with spiny armature. Secondary appendage 



of first antenna shorter than flagellum. 



b. Basal article of peduncle of first antenna unarmed. Secondary appendage of 

 first antenna one-fourth as long as flagellum. Long spiny processes on either 

 side of head, one pair at the place of fusion of the first thoracic segment with 

 the head, the other pair anterior to these, being the produced outer angles 

 of the ocular lobes. Last segment of abdomen with posterior margin slightly 

 emarginate, a small lobe being placed in the center of the emargination. 



Apseudes grucilis Norman and Stebbing 



See Sars, Crust, of Norway, II, 1899, p. 5, and Norman and Stebbing, Trans. 

 Zool. Soc., London, XII, 1886, p. 79, for characters given below. 



