CRAYPISII, LOBSTERS, SPIDERS, AND INSECTS 139 



plex and interesting. 

 From the egg there 

 hatclies a peculiar form, 

 having a long abdomen, 

 few or no appeiadages, 

 and large compound 

 eyes. Thif: is the larval 

 form and is called zoea 

 (Fig. 78). After molt- 

 ing several times, the 

 larva changes to a form 

 called megalops (Fig. 79). 

 This form somewhat i'eseml)les 



Fig. 79. — Megalopa of a crab. 



■Zoea of a crab. 



adult crab. Finally, 

 the form, megalops, 

 gradually changes, by 

 additional molts, mto 

 the adult crab. 



The common blue 

 cral), fomid along the 

 Atlantic coast from 

 Cape Cod south, and 

 ill the Gulf, is our 

 most important edible 

 cralj. The so-called 

 " soft-shelled " crabs 

 are simply blue crabs 

 that are caught just 

 after they have cast 

 theoldhardskin. The 

 body is then soft and 

 the flesh is considered 

 a great dehcacy. 



