THOEACOSTBACA. 



407 



lobed and used as jaws : the four anterior maxillipeds are biramous 

 and act as birainous swimming feet : and behind them, in the macru- 

 rous Decapods, the niaxilliped of the third pair also appears as a 

 biranious swimming foot. Gills are as yet wanting, being repre- 



FIG. 367. Larva of Pi-naeus Caftev Fr. Miiller). a, Nauplius form seen from the dorsal sur- 

 face, b, Metanauplius stage seen from the left side; MX', anterior mnxilkr; .1/0-'', pos- 

 terior maxilla? ; Grl, sixth and seventh pairs of appendages or first and second 

 niaxillipeds. c, Zosea stage ; 0, eyes. 



sented by the thin surfaces of the sides of the cephalo-thoraeic 

 shield, beneath which a continual current of water flowing from 

 lit -hind forwards is kept up. A short heart with one or two pairs 



