244 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



Remarks. — This new species may be recognized by the long apical 

 setae on the caudal rami, by the structure of the first and fifth legs 

 in the female, and by the curious prehensile organ on the basipod of 

 the first leg in the male. 



Genus AMEIRA Boeck, 1865 



Body slender and somewhat compressed ; head fused with the first 

 segment and shorter than the rest of the metasome ; rostrum almost 

 obsolete; urosome 4-segmented, nearly as long as the metasome, its 

 segments much less coarsely spinulose than in Nitocra; genital seg- 

 ment divided in the middle ; caudal rami short and without spinules. 

 First antennae 8-segmented; exopod of second antennae narrow and 

 1-segmented; rami of first four pairs of legs 3-segmented, none of 

 the endopods modified in the male ; first legs prehensile, the endopods 

 much longer than the exopods; fifth legs 2-segmented of the usual 

 pattern. 



KEry TO THE SPECIES 



FEMALES 



1. Basal segment of first endopod longer than 2 diistal segments 



combined ; basal expansion of fiftli legs with 4 setae 2 



Basal segment of first endopod shorter than 2 distal segments 



combined; basal expansion of fifth legs with 5 setae simplex (p. 244) 



2. First antennae no longer than cephalic segment; basal segment 



of first endopod but little longer than 2 distal segments com- 

 bined tau (p. 245) 



First antennae much longer than cephalic segment ; basal segment 

 of first endopod twice as long as 2 distal segments com- 

 bined tenuicornis (p. 247) 



MALES 



1. Endopod of first legs much longer than exopod ; basal expansion 



of fifth legs with 2 very unequal setae 2 



Rami of first legs equal in length ; basal expansion of fifth legs 



with 3 subequal setae simplex (p. 244) 



2. The 2 distal segments of first endopod equal in length; middle 



segment of first exopod with an inner seta tau (p. 245) 



The 2 distal segments of first endopod very unequal in length ; 

 middle segment of first exopod without inner seta tenuicornis (p. 247) 



AMEIRA SIMPLEX Norman and T. Scott 



Figure 162 



Ameira simplex Nobman and Scott, Ann. Mag. Nat. Hist., ser. 7, vol. 15, p. 291, 

 1906.— Sars, Crustacea of Norway, vol. 5, p. 219, pi. 144, 1907. 



Occurrence. — Two females from one of the brackish ponds on 

 Chappaquiddick Island, August, 1926 ; 15 males and females washed 

 from the sand on the bathing beach at Dennis, north shore of Cape 

 Cod. 



