86 



HISTORY OF CRUSTACEA. 



CHAP. IX. 



is situated. The form in this Nauplius-brood is ex- 

 tremely various, it is sometimes compressed laterally, 

 sometimes flat, sometimes elongated, sometimes oval, 

 sometimes round or even broader than long, and so 

 forth. The changes which the first larval stages under- 

 go during the progress of growth, consist essentially in 

 an extension of the body and the sprouting forth of 

 new limbs. " The following stage already displays a 



fourth pair of ex- 

 tremities, the future 

 maxilke." Then fol- 

 io w at once three new 

 pairs of limbs (the 

 maxillipedes and the 

 two anterior pairs of 

 natatory feet). The 

 larva still continues 

 like a Nauplius, as 

 the three anterior 

 pairs of limbs repre- 

 sent rowing feet ; at 

 the next moult it is 

 converted into the 

 youngest Cyclops- 

 like state, when it 

 resembles the adult animal in the structure of the 

 antennae and buccal organs, although the number of 

 limbs and body-segments is still much less, for only the 



Fig. 54. 



4 Figs. 53 and 54. Nauplii of Copepoda, the former magn. 90, the 

 latter 180 diam. 



