350 



CRUSTACEA. 



Fig. 165. 



the body, possesses no 

 false feet ; and the ter- 

 minal joint is crescent- 

 shaped, and covered 

 with long spines. The 

 eyes are very large, and 

 a long beak projects 

 from the lower surface 

 of the head. 



In a more advanced 

 stage of growth the 

 creature assumes a to- 

 tally different shape, 

 (Jig- 165,) under which 

 form it has been known 

 to naturalists by the 

 name of Megalopa. 

 The eyes become pe- 



dunculated, the cepha- 



lo-thorax rounded, the 

 tail flat and provided 



with false feet, 



and the chelae 



and ambulatory 



extremities well 



developed. 

 A subsequent 



moult gives it 



the appearance 



of a perfect 



crab ; and then 



only does the 



abdomen become 



folded under the 



thorax, and the 



normal form of the species recognisable (fig. 166), 



Fig. 166. 



