WORMS 



3°7 



out the tropical and temperate seas. In 0. edulis the sexes are united in one 

 individual, but in another European species, 0. angulata, as in the American oyster, 

 0. Virginia, they are separate. Two other Atlantic species of the American coast, 

 0. concophila and 0. lurida, are both edible ; and the edible species of the Pacific 

 are all different in widely separated localities. 





HERMIONE HYSTRIX. 



Worms. 



In the large group of worms or annelids the members of the 

 many-bristled section are exclusively marine. Conspicuous among 

 these is the sea-mouse (Aphrodite aculeata), whose body is covered with iridescent, 

 fringe-like bristles glittering like gold. In this form the fifteen pairs of so-called 



ORANGE COMB-STAR. 



elytra are hidden beneath a felting of hairs ; but in the allied Hermione, which is 

 also European, the felting is absent and the elytra are exposed. In another group 

 of bristle-bearing annelids, which live in tubes and burrows, is included the lug- 

 worm (Arcnicola marina) so common on the flat sandy shores of Europe between 



