236 



BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



Distribution. — New Mexico (Herrick, Marsh). 



Color. — Transparent with a whitish cast and without pigment 

 markings of any kind ; eye invisible. 



Female. — Cephalic segment much shorter but wider than the rest 

 of the metasome; rostrum prominent and peglike; urosome half the 

 length of the metasome, the segments of both divisions fringed 

 posteriorly with spinules; genital segment not divided; caudal rami 

 one-half longer than wide, the inner apical seta twice the length of 

 the outer. 



Kami of first legs about equal, the distal segment of the endopod 

 one-fourth longer than the basal, with a slender apical spine much 

 longer than the segment and sparsely denticulate.* Inside of the 



Figure 157.^ — Marshia hrevicaudata: a. Female, dorsal; 6, female, fifth 

 leg ; c, female, first leg ; d, female, fourth leg 



spine and close to it are two plumose setae, the nearest one twice the 

 length of the spine, the other only half that length. The outer spines 

 of the exopod are rather blunt and stout, and each segment has two 

 or three outer spinules. The fourth endopod is shorter than the 

 basal exopod segment; in some specimens it showed two distinct 

 segments, the distal one three times the length of the basal ; in other 

 specimens the two segments were completely fused without a trace 

 of demarcation. Tliis endopod has two apical setae, the outer one 

 plumose and five times as long as the inner, which is filiform. In 

 the fourth exopod the two apical setae and the inner seta of the 

 middle segment are exceptionally long and stout, while the spines on 

 the outer margins of all three segments are slender and weak. In the 

 fifth legs the outer lobe of the basal segment is distinctly indicated 

 and bears a long smooth seta; the inner expansion is quadrangular 



