de | « ee 
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. ae 
Viewed from end (Fig. 25) shell is oval, a little higher than wide. ¢ 
Antennules (Fig. 25) and antenne as usual in genus Cypris. Ee: 
The mandible (Fig. 26) terminates in four large teeth; between each <a 
two of these teeth there is a short, slender rod. The mandibular palp _ a 
consists of four joints. The first joint is very large, about as large as ain, 
the combined lengths of the other three; it bears about the middle of 
its dorsal surface a branchial appendage, which in turn bears four ei) 
long sete; and from the distal fifth of its ventral surface arise two long | 
sete. The antepenultimate joint is very short; from the distal half 
of its dorsal surface arise two long sets and one short one. The — 
penultimate joint is long; from its disto dorsal extremity arise three ae 
long and one short sets; from the disto-ventral angle of the shell 
arise two short sete. 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. ae 
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 about 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 ye 
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. Hntad of this terminal claw is another - 
long claw; further entad arises a short seta. Post-abdomen of female 
is straighter, otherwise the same. 
