r.1'2 



MOLLUSC A, 



THE CARDIACEA. 



These iiicliulo a frroat variety of species — two liuiidre*! in lumiher — bearing the general name 



of Cockle. Many <>t' tlieni are elegantly marked with radi- 

 ating ribs, and these are sometimes ornamented with spines 

 of various forms. They are usually active animals, often 

 springing to a considerable height by means of the strong 

 bent feet. They generally live concealed in the mud. The 

 Common Cockle, Cardium edule, is eaten in large quantities 

 on the coasts of Europe. The C. Junonoe is a very beautiful 

 species. The great assemblage of the different kinds is in the 

 Indian Ocean, though some of the species are found in all seas. 

 Several small species, as the C. Grcenlandicuvi, the C Mar- 

 tinii, &c., are found on our coasts. 



TOE CAUDIUM JUNONJJ. 



THE HIPl'OI'US MACULATUS. 



THE CHAMACEA. 



This group includes several genera of bi- 

 valved moUuscji, sometimes called Clams, 

 and mostly found in tropical countries ; cer- 

 tain species are the largest animals belong- 

 ing to this division of the animal kingdom. 



Of the genus Chama, there are more 

 than twenty species, generally found at- 

 tached to submarine substances as rocks 

 and corals ; they are of various forms and 

 sizes, though generally large. The Giant 

 Clam, Tridacna r/igas, is the largest of 

 known shell-fish, the two valves some- 

 times weighing five hundred pounds, and 

 the animal from twenty to thirty pounds. 

 It is found along the shores of the Polyne- 

 sian and Asiatic Islands, where the flesh is 

 eaten raw by the natives. The interior of 

 the shell is beautiful, being white and like 

 polished marble ; the form is also elegant, 

 whence it is much sought for as an orna- 

 ment for fountains, grottoes, and flower- 

 gardens. It is also employed as fonts for 

 holy water in Catholic churches in Europe. 

 One of enormous dimensions is used for this 

 purpose in the church of St. Sulpice, Paris. 

 The shells of the Hippopns maculatus are 

 smaller but are very beautiful, and are used 

 in the manufacture of various ornamental 

 ^.„„ articles, as inkstands, &c. 

 '^■^i^ Broderip says of the chamacea, that they 

 j^ have been found at various depths, from the 

 .s:^^ surface to seventeen fathoms ; their shape is 

 usually determined by the body to which 

 they are fixed ; their color seems to be in- 

 fluenced by their exposure to the light. The 

 byssus by which the T. f/ir/as is attached to 

 the rocks is so firm and tough, that it can 

 only be severed by an ax. 



