CR USTAGEASYSTEMA TIG RE VIE W 



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



Body small, with 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\, Antennule ; a*, second (rowing) 

 antenna; I, hepatic csecum ; au, eye; d, intestine; sd, shell gland; h, heart; bnt, brood cavity; 

 aft, abdomen ; 6)-, branchial sac ; fi-fs, trunk feet ; g, brain. 



m. 



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

 posterior antennas ; fs, frontal organ ; oc, unpaired eye ; aw, paired eye ; h, heart ; m, stomach ; s, 

 shell ; f-2, cleaning foot ; g, sexual organs (?) ; fi, first foot ; mx-z, second maxilla ; sm, shell muscle, 

 mxi, first maxilla ; oft, 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 

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