332 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



Viewed from below (Fig. 24) same as when viewed from above. 

 Line of contact of valves sinuate. 



Viewed from end (Fig, 25) shell is oval, a little higher than wide. 



Antennules (Fig. 25) and antennse as usual in genus Cypris. 



The mandible (Fig. 26) terminates in four large teeth; between each 

 two of these teeth there is a short, slender rod. The mandibular palp 

 consists of four joints. The first joint is very large, about as large as 

 the combined lengths of the other three; it bears about the middle of 

 its dorsal surface a branchial appendage, which in turn bears four 

 long set?e; and from the distal fifth of its ventral surface arise two long 

 setse. The antepenultimate joint is very short; from the distal half 

 of its dorsal surface arise two long setae and one short one. The 

 penultimate joint is long; from its disto dorsal extremity arise three 

 long and one short setae; from the disto- ventral angle of the shell 

 arise two short setae. The terminal joint is very narrow and about 

 as short as the antepenultimate joint; at its tip it bears four short 

 claws. 



The biarticulate claws on the first mandibular process of the first 

 maxilla are smooth. 



The first foot of the male (Fig. 27) is composed of five joints. The 

 second joint is large. The antepenultimate joint is al)out as long as 

 the preceding joint. From its disto caudal margin arises a medium 

 sized seta, and from its disto cephalic margin arises a somewhat 

 smaller seta. The terminal joint is about the same size as the penul- 

 timate. From its disto-caudal margin arise a medium size seta and a 

 small spine; from its disto-cephalic margin arises a very short spine. 

 From the distal end of joint arises a long claw; the claw is about as 

 long as the combined lengths of the three distal joints. The claw is 

 composed of a short basal and a long terminal portion. At the disto- 

 caudal portion of the basal joint of claw there is a short seta; at the 

 disto-cephalic margin of the same joint there is a somewhat smaller 

 seta. A row of fine hairs extends along the middle portions of the 

 caudal margin of the terminal joint of the claw. 



In the second foot of the male the antepenultimate joint is medium 

 sized. From about the middle of this joint arises a median seta, and 

 from the disto-caudal margin a long seta. The penultimate joint is 

 the longest joint; from its disto-cephalic margin arises a median spine. 

 The terminal joint is about as long as the antepenult; from the middle 

 of its cephalic border arises a short seta; from its tip arises a short 

 seta; from its tip a more or less curved short claw and a median seta. 



The post-abdomen (Fig. 29) of male is curved. At its tip there is 

 a long claw and a short seta. Entad of this terminal claw is another 

 long claw; further entad arises a short seta. Post-abdomen of female 

 is straighter, otherAvise the same. 



