CRUSTACEA SYSTEMATIC REVIEW 



289 



Sub-Order 2. Cladocera (Daphnidse), Water Fleas. 



Body small, Avith few indistinct segments and 4 to 6 pairs of swimming feet. The 

 posterior antennae are large rowing feet. 



/ 



Fig. 192. Daphnia similis, young female (after Glaus). a l5 Antennule ; a 2 , second (rowing) 

 antenna ; Z, hepatic caecum ; a?, eye ; d, intestine ; sd, shell gland ; h, heart ; bru, brood cavity ; 

 ab, abdomen ; br, branchial sac ; f r f 5 , trunk feet ; g, brain. 



a-., 



Fig. 193. Cypridina mediterranea, female, from the side (after Glaus). OL Anterior, a 2 , 

 posterior antennae ; fs, frontal organ ; oc, unpaired eye ; au, paired eye ; h, heart ; in, stomach ; ~s, 

 shell ; / 2 , cleaning foot ; g, sexual organs (?) ; / ; , first foot ; mx. 2 , second maxilla ; sm, shell muscle,' 

 mxi, first maxilla ; 06, upper lip ; md, mandible. 



Branchial sacs may be wanting. With bivalve shell. Head freely projecting. 

 Female with dorsal brood cavity between shell and trunk. Heart sac-shaped with 

 VOL. I 



