METAMORPHOSES OF THE CRUSTACEA. 



281 



In the Opossum-shrimps (Mysis) the young does 

 not leave the pouch of the mother until it is fully 



FIG. 73. Penteus semuulcatus. A, adult (after deHaan. \ nat. size) ; 

 B, Zoea, and C, less advanced Zosea of a species of Pencem. D, 

 Nauplius. (B, C, and D, after Fritz Muller.) 



