74 



THE LIFE OF CRUSTACEA 



of it, and each has at its base a hooked spine which 

 projects inwards and serves for seizing particles of 

 food and passing them into the mouth ; the antennae 

 of the nauplius, in fact, serve as jaws, while it is 

 only later that the mandibles take on this function. 



FIG. 29 LARVAL STAGES OF THE PRAWN Penceus (SEE 



PLATE IV.). x 45. (After F. Muller.) 



A, Nauplius ; B, young zoea ; C, older zoea ; D, early " schizopod " 



stage 



In the further development of the larva, the body 

 increases in length and becomes divided into somites 

 which increase in number by new somites appear- 

 ing behind those already marked off ; the rudiments 



