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BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



and a filiform seta, the third one spiniform and minutely denticu- 

 late. Fourth endopod also spiniform, nearly as long as the entire 

 exopod and ciliated at its tip. Fifth leg with the usual outer basal 

 process, a broad spinelike inner expansion, unarmed, and between 

 the two a short process carrying two setae and representing the 



distal segment. Total length, 0.4-0,5 mm. 

 Male. — As large as the female; first an- 

 tennae geniculate, fourth segment enlarged, 

 the three terminal segments folded back 

 against its posterior surface. First and 

 second legs like those of the female; third 

 legs completely transformed and unlike 

 anything found among harpactids. The 

 rami of each leg are curved inward and 

 completely fused except at the tip, where 

 they are separated into two fingerlike proc- 

 esses, each of which ends in a hyaline mem- 

 brane. The outer process is articulated 

 with the fused portion and ends in a sharp 

 point, the inner one is immovable and 

 squarely truncated. The fourth endopod 

 reaches nearly the tip of the second exoj)od 

 segment and is obliquely truncated at its 

 distal end and armed there with an outer 

 rounded knob, an inner sharp point, and, 

 between the two, five or six short setae. In- 

 side of the endopod the distal corner of the 

 second basipod projects as a rounded proc- 

 ess bearing three apical fingerlike append- 

 ages. Each fifth leg is a tiny almost cir- 

 cular lamella, with two setae and without 

 distinction of parts. Total length, 0.4- 

 0.5 mm. 



Remarks. — This is the first record of the 

 species outside of Austria. Here in the 

 ponds mentioned above it lives in the sand an inch or more beneath 

 the surface and close to the water's edge. Every joint in the body 

 seems capable of free motion, and it crawls about with the sinuous 

 movements of an annelid. Its swimming is also more like that of 

 a worm than of a copepod. It may be recognized by these move- 

 ments, by the caudal rami and fifth legs of the female, and by the 

 peculiar third legs of the male. 



Figure 17 8 . — Parastenocari* 

 brevipes: a. Female, dorsal ; 

 b, female, fifth leg ; c, d, 

 male, third and fifth legs 



