462 Illinois State Laboratory of Natural History. 



distal end and several irregularly scattered plumose cilia 

 on its inner edge, also with a stiff seta on its inner edge 

 situated slightly below the middle and reaching to the 

 distal end of the segment; antepenultimate segment as 

 long as the penultimate, covered with scattered plumose 

 cilia and bearing a seta at its inner distal angle which is 

 slightly longer than the seta on the penultimate seg- 

 ment. 



Caudal rami rather long and narrow (Fig. 9), nearly 

 straight, two and two fifths times as long as the ter- 

 minal claw% which is weakly bent and smooth; subter- 

 minal claw four fifths as long as the terminal one, pro- 

 vided with a comb of long teeth near the tip. Terminal 

 seta two fifths as long as the terminal claw ; dorsal seta 

 situated at the middle of the ramus, scarcely as long as 

 the ramus is wide. 



This Cypria occurs quite abundantly in the collections 

 of the Biological Station, made near Havana, Illinois. 



Cypria obesa n. sp. (PI. XLYIII., Fig. 1-5.) 



Length .78 mm., height .48 mm., width .33 mm. 



Shell plump, clear to brownish yellow, with a few scat- 

 tered elevations on its surface, but not especially marked 

 in any way. Muscle impressions quite small. Seen from 

 the side, the shell is of a regular suboval form with a 

 straight ventral edge, three fifths as high as long. 



Second antennge of male six-segmented ; terminal seg- 

 ment twice as long as wide ; inner terminal claw half the 

 length of the outer; apical part of fourth segment with 

 two "sense setse" reaching to the tip of the terminal seg- 

 ment; sense club on the inner edge of the third seg- 

 ment rather short, extending slightly beyond the upper 

 quarter of the segment; natatory setse only twice as 

 long as the distance between their place of insertion and 

 tips of terminal claws. 



Palp of right maxilla of male (Fig. 5) larger than 

 that of the left maxilla (Fig. 4), and formed as shown 

 in the figrure. 



