North American Fresh-wnter Ostracoda. 443 



vertical line passino^ through the eye-spot. The anterior 

 part also is tipped with a dark patch. The form and 

 intensity of coloration of these patches seem to be va- 

 riable, but in general they are as described above. The 

 surface of the shell is quite rough, as though covered with 

 a loose scaly epithelium, and rather thickly set with 

 short hairs. 



Seen from the side, the shell is oblong-ovate, highest 

 at its anterior third, sloping rather quickly to the 

 posterior extremity, which is somewhat narrower than 

 the anterior. 



Seen from above, the shell is elongate-oval, the ante- 

 rior end somewhat more acutely pointed than the pos- 

 terior; widest at the middle. 



Maxilla stout, the spines on its first process toothed. 



Terminal segment of second foot one thirteenth as long 

 as the penultimate segment, which is seven ninths as 

 long as the preceding one. Terminal claw much bent and 

 twice as long as the terminal segment. 



Caudal rami (Fig. 5) long, slender, straight, more 

 than twenty times as long as wide, the dorsal edge 

 finely toothed. Terminal claw slightly bent, slender, 

 finely toothed, and one half as long as the ramus; sub- 

 terminal claw two thirds the length of the terminal one, 

 straight, finely toothed near the tip. Terminal seta 

 slender, about half as long as terminal claw, and twice 

 as long as the dorsal seta, which is one and a half times 

 width of ramus from the subterminal claw. 



The specimens studied by me were obtained from a 

 pond south of Urbana, 111., April 16, 1892, and are now 

 in the collection of the Illinois State Laboratory of Nat- 

 ural History. 



The species occurs in Great Britain, Germany, and 

 Sweden; and, in America, in Mexico and New Mexico 

 (Herrick), at Cincinnati, Ohio (Turner), and at Urbana, 

 111. (Coll. 111. State Lab. Nat. Hist.). 



