lia ZOOLOGY. 



suckers, excepting those at the end of the arms, which are- 

 tentacle-like. Ve have already described the common star- 

 fish of our north-eastern coast, Asterias Forhesli of Desor- 

 (Fig. 74). This and the allied varieties are abundant oa 

 mussel and oyster beds, being Tery injurious to the latter, 

 iThich serve them as food. The star-flsh projects its capa- 

 cious stomach, turning it inside out, between the open 

 valves of the oyster, and sucks in the soft parts, in this way 

 doing much damage to the oyster-beds of the southern coast 

 of Xew England. 





Hg- 74.—Agterias JbrbesU, natnra] size.— After A. Agassi* 



The bodies of star-fishes as well as sea-urchins (Echini) 

 are covered with. pedicellari(B, which in the former are situ- 

 ated around the base of the spines on the upper side of the 

 body. They are pineer-like, consisting of but two prongs. 

 In the sea-urchins they are three-pronged, and scattered ir- 

 regularly over the surface of the body. Their use is not 

 really known, .s tar-fish have the sense of smell. 



The development of this species (and its ally or varietVy 

 A. berijJimis) has been studied by A. Agtissiz. " After pass- 



