402 



ELEMENTS OF BIOLOGY 



TRILOB/TE 



LAR^A or A TRILOBITE 



LARVA OF A KING CRAB KING CRAB 



Fig. 222. — A modern king crab, its larva, and an extinct trilobitc and its larva. 

 (Partly after Lucas: Animals of the Past, published by McClure, Phillips, and 

 Company.) 



