242 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



exopod of second antenna enlarged distally, with three apical setae; 

 basal endopod segment of first legs longer than the entire exopod, 

 the two terminal segments short, equal, and to- 

 gether half as long as basal segment; the three fol- 

 lowing pairs of legs -with a reduced number of 

 setae on the distal segments of both rami; distal 

 segment of fifth legs small oval, with six setae, 

 the third inner one filiform, basal expansion reach- 

 ing middle of distal segment, with five setae, the 

 second outer one longest. Total length, 0.6-0.65 mm. 

 Male. — Unknown. 



Remarks. — This species may be recognized by the 



Figure 161.— spines on the anal segment and caudal rami and by 



N i t o r a ^}^g structure of the first and fifth legs. Sars said 



male, fifth leg of it '" " It is a strictly littoral species, found in more 



or less brackish water, and occasionally also in tidal 



pools." This is its first record from our American shores, but it is 



likely to be found in the sands of other beaches. 



NITOCRA CHELIFER, new species 



Plate 8 



Occurrence. — Fifty specimens, including both sexes, were washed 

 from the sand on the shore of Katama Bay, Marthas Vineyard, 

 August, 1927. The male holotype is U.S.N.M. No. 63427. 



Color. — Body fairly transparent, of a whitish color but without 

 any pigment markings; ovaries, oviducts, and eggs faintly tinged 

 with blue ; eye dull red. 



FemMe. — Body elongate and narrow, five times as long as wide; 

 metasome somewhat compressed and strongly arched dorsally, the 

 movable joint between the fourth and fifth segments rather con- 

 spicuous; cephalic segment as long as the three following segments 

 combined; rostrum narrow and short but well defined at its base. 

 Urosome three-fourths as long as metasome ; genital segment without 

 a trace of division, about as long as the two basal segments of the 

 abdomen combined, with slightly convex lateral margins. Abdomen 

 3-segmented, anal segment a little shorter than the penultimate seg- 

 ment, with two transverse rows of spinules on each lateral surface; 

 anal operculum at about the center of the dorsal surface, fringed 

 with slender spinules. Caudal rami wider than long, each with a 

 transverse row of spinules across its dorsal surface ; inner apical seta 

 four-fifths as long as the whole body, outer one one-third as long, 

 both jointed near the bases. 



