North American Fresh-water Ostracoda. 453 



is bluutly pointed or arched ; side contours almost 

 parallel for half the length of the animal. 



Second pair of antennae of female (Fig. 1) shorter and 

 thicker than usual, the second segment being as wide as 

 long, the antepenultimate but slightly- longer than 

 broad, and the penultimate four fifths as wide as long 

 and about three times as long as the terminal segment. 

 Terminal claws smooth, about as long as the last two 

 segments taken together. 



First pair of feet (Fig. 5) five-segmented; terminal 

 segment conical, approximately' as long as the penulti- 

 mate, which is about as wide as long; antepenultimate 

 segment like the penultimate, — the three combined being 

 but an eighth longer than the second segment. Terminal 

 claw as long as the last three segments. 



Second pair of feet (Fig. 2) five-segmented, the fourth 

 segment being undivided as in the great majority of the 

 species of Candona. Foot small; second, third, and 

 fourth segments of the same size; constricted at the 

 joints, and not especially armed in any way except for 

 the presence of several minute spines on each segment 

 (Fig. 2). Terminal segment as long as broad, the shorter 

 terminal seta two and a half times as long as the ter- 

 minal segment, while the similarly directed seta is two 

 and two thirds times as long as the shorter one. 



Caudal rami (Fig. 6) rather short, stout, bent; ter- 

 minal claw little more than half as long, stout, finely 

 toothed, scimitar-like. The subterminal claw is strongly 

 S-shaped and prominently toothed on the upper curve, 

 and as the caudal rami commonly project from the shell, 

 this structure affords a ready means of distinguishing 

 the species at a glance. Dorsal seta of ramus twice the 

 width of the ramus from the subterminal claw, bent up- 

 ward at tip, and two thirds the length of the subter. 

 minal claw ; terminal seta very small, scarcely half as 

 long as the subterminal claw. 



This species may be readily distinguished from O. sig- 

 moides by the character of the caudal claws and the 



