No. 395.] WORTH-AMERICAN INVERTEBRATES. 883 
appendage of the intestine unusually short ; ovarian tubes much elongated.” 
[Sharpe.] No American species known. 
6. Cypridopsis Brady, 1867. 
The first antenna is seven-jointed, the second five-jointed. The five nata- 
tory sete of the second antenna are long and plumose. The branchia of 
the second maxilla consists either of a plate bearing five plumose sete or 
else of two sete inserted directly on the blade. Second foot five-jointed, 
bearing at its extremity a strong chitinous claw. Caudal rami rudimentary, 
flagellum-like. Parthenogenetic. 
a. Branchia of second maxilla with five seta. Shell marked with three 
more or less transverse, dark bands, which are confined to the 
dorsal and lateral surfaces. Very plump. Common. Length 0.54 
. to 0.70 mm. . C. cypridopsis (O. F. Mueller) 
aa. Branchia of the sönd daan fornia of two setæ. 
6. Caudal ramus cylindrical and turgid, suddenly narrowing to a 
posie .. C. newtoni Brady and Robertson 
66. Caudal ramus Doai; eradually narrowing to a bristle. 
c. Natatory setae of the second antennz reaching to the tip of 
the terminal claws. Shell pale green 
C. villosa (Jurine) 
cc. Natatory sete of the second antenne reaching beyond the 
end of the terminal claws. Shell grass green on dorsal 
We ee a . C. smaragdina Vávra 
7- Cyprinotus Brady, 1885. 
Shell rather thin, compressed, oval or subtriangular, height exceeding 
half the length, dorsal margin strongly arched, ventral aspect straight. 
Valves usually unequal, the left overlapping the right. The free edges of 
the left valve smooth, cephalic and caudal edges usually bordered with a 
hyaline flange. The free cephalic edge of the right valve usually armed 
with tuberculiform teeth. Natatory sete of the second antenne reach 
beyond the tips of the terminal claws. Caudal rami slender with smooth 
or very finely pectinated claws. Propagation sexual. Copulatory organs 
small, with an outer linguiform obtuse plate. The cylindrical core of 
Zenker’s organ bears numerous wreaths of spines. 
a. Length more than three mm. ; color bluish white, with a group of 
scattered, large, sordid, r punctures about the middle of 
each valve > is aodou eg C frandis Chambers 
aa. Length between one and two mm 
6. Dorsal seta of caudal ramus more than half the length of the sub- ` 
terminal claw. 
