LEPTOSTRACA, SCHIZOPODA, DECAPODA. 



B 



153 



Fig. 77.— Five embryos of Mysis (after Nusbaum). A, youngest Nauplius stage. B, older 

 Nauplius stage in profile. C, Nauplius after the disappearance of the vitelline membrane, 

 in three-quarters profile. D, later Nauplius stage with the Nauplius integument (u). E, 

 larva with thoracic limbs, a', first antenna; a", second antenna; c, vitelline membran 

 d, dorsal organ ; md, mandible ; n, Nauplius integument ; o, optic lobe ; p, rudiment of the 

 compound eye ; s, caudal region. 



