240 



BULLETIN 158, UNITED STATES NATIONAL MUSEUM 



Genus NITOCRA Boeck, 1865 



Body slender and cylindrical, with no sharp distinction between 

 metasome and urosome ; head fused with the first segment and shorter 

 than the rest of the thorax ; urosome two-thirds as long as metasome 

 and 4-segmented, the segments coarsely spinulose along their pos- 

 terior margins; genital segment divided in the middle; anal oper- 

 culum with a denticulate margin; caudal rami short and covered 

 with spines. First antennae 8-segmented, the two basal segments 

 enlarged; endopod of second antenna 3-segmented, the 1-segmented 

 exopod attached to the end of the basal segment ; rami of first four 

 pairs of legs 3-segmented, fir^t legs prehensile; fifth legs 2-seg- 

 mented, of the usual pattern ; a single ovisac. 



KEY TO THE SPECIES (BOTH SEXES) 



1. Rami of first legs equal ; 2 terminal segments of first endopod 



also equal, and together as long as basal segment spinipes (p. 240) 



Endopod of first legs much longer than exopod 2 



2. The 2 terminal segments of first endopod equal, and together less 



than half as long as basal segment typica (p. 241) 



Apical segment of first endopod twice as long as second segment, 



two together longer than basal segment chelifera, new species (p. 242) 



NITOCRA SPINIPES Boeck 



FiGUEB 160 



Nitocra spinipes Boeck, Forh. Vid.-Selsk. Christiania, 1864, p. 274. — Sars, Crus- 

 tacea of Norway, vol. 5, p. 213, pi. 139, 1907. 



Occurrence. — Found in abundance in one of the brackish ponds on 

 Chappaquiddick Island, July, 1926; found sparingly in the French 



Watering Place on Naushon 

 Island, and in Quisset Pond, 

 Falmouth. 



Distribution. — S c o 1 1 i s h 

 coast (T. Scott) ; Norwegian 

 coast (Boeck, Sars) ; Adri- 

 atic (Carazzi, Pesta) ; Nova 

 Zembla (Gurney) ; Baltic 

 coast (van Douwe) ; coast of 

 England ( Gurney ) . 



Color. — Female transpar- 

 ent, head whitish spotted 

 with red, thorax and abdo- 

 men pale pinkish red, deep- 

 est in the fifth segment of 

 the thorax and along the lateral margins of the segments in the abdo- 

 men; eye bright ruby red; eggs pale pink with bright red centers; 



Figure 160. — 'Nitocra spinipes: a. Female, dor- 

 sal ; 6, female, first leg ; c, female, fifth leg ; 

 d, male, fifth leg 



