220 



Fig. 152. — Development of Sac- 

 culina. — After Delage. (Not 

 drawn to scale.) 



A, Free-swimming nauplius, with three 

 pairs of appendages ; B, pupa stage ; C, 

 adult protruding from the abdomen of a 

 crab. 



Fig. 153. — Daphnia, 



Eye; A'^, second antenna; A^, first antenna; dg., 

 digestive caeca ; s.g.^ shell gland ; go., gonad ; h., heart 

 in pericardium ; 0., ovum ; B.p., brood-pouch ; sp., 

 spine ; /., furca ; s., setae ; Ab., rudimentary abdomen ; 

 t., caudal fork ;g., gut ; 1-5, thoracic limbs. 



Fig. 154. — Cypris, side view, 

 after removal of one valve. 

 — -After Zenker. 



e.. Eye \ Ai, first antennae ; A2, second 

 antenna ; MN, mandibles ; mxi, 

 first maxilla ; mx2, second maxilla; 

 /i, /2, thoracic legs ; Ab, rudi- 

 mentary abdomen. 



