THI-: OSTRACODA 



807 



8 (7) Shell faintly reticulate, with one lateral furrow. Furca tapering to a 

 seta Hke extremity (Fig. 1251 b). 



Limnuythac illinoisensis Sharpc 1897 



k: 



scKnirnictl 

 alnxif wvrn 



y 

 1. 

 ot iitali alliK-ti Miih 



Itvth at tip Sandy J. 

 Illinois Kivrr. I^ayuiu. iuvi ix».t 

 shores. May. 



"I 



Kir. ij<i 

 Limmi(\lkrrf iiii»(ni#»itt 



sal vir». <^ J .:. . 



flagcilum. J 

 maJf 



'«) t> 



9 (10) Abdomen without furca. Second legs not backwanlly uirtM tc(i. 



Family I)AK\visruD\i . 

 Darwinula stcvcnsoni Hraiiy and RolxTlson 1870. 



Length 0.70 to 0.80 mm. Kicht shell <-■. < 

 left. Abdomen ending in a olindriial un; 

 (Fig. 1252a). Sandy or muddy Ixiito"- 

 improvisa Turner i8qs, is a synonym 



Fig. ijsj. 

 Dardinula slnensoni. (a) Tip of abdomen. X 166. 



10 (9) Abdomen with furca. Second legs backwardly bent. 



Pamily C'yprididak . 



11 (12) Furca rudimentary, with a long seta at tip (Fig. 1253)- • 



12 (ii) Furca band-like, with claws and setae at tip (Fie i-^^j) . 



13 



Natatory setae of second antennae long, reaching .it kaM l.» iji>s 

 of terminal claws. Second foot beak-shajH-d at tip. willi a 

 terminal claw. . . . Subfamily Cvpkidopsin v J 



14 (15) Shell broad from above, tumid. Second antenna five-s<-gnicntrtl 



Only one species in North America. The "^f » ^/^^P^"}^" ."^ 

 American ostracod. . . CypnchpstsvuiiuiO.V.Mu]}^ 



Length 0.60 to 0.70 mm., plump. Markc«l <lor«lK 

 ith three prominent dark han.is. \ cry comn»on. « 



with three i)ror 

 are present. 



Fig. 1253. CyprUcpsis tuitt*. Furca. X 1 So. 



