MOLLUSCA. 



addition of a jointed stalk, which is made to pro- 

 ceed downwards from the centre of the whole 

 assemblage of rays, and which is to serve as 

 a common stem for sustaining the whole mass ; 

 while the branches themselves are carried up, 

 and folded inwards. The lower joint of the 

 foot-stalk is a little expanded, in order to pro- 

 cure a more extensive base of support ; and the 

 whole structure thus presents a remarkable re- 

 semblance to a liliaceous plant. 



CHAPTER III. 



MOLLUSCA. 

 1 . Mollusca in general. 



THE series of animal structures, arranged ac- 

 cording to their mechanical functions, conducts 

 us next to the Mollusca; an assemblage of 

 beings which was first recognised as constituting 

 one of the primary divisions of the animal king- 

 dom by Cuvier, the greatest naturalist of modern 

 times. A vast multitude of species, possessing 

 in common many remarkable physiological cha- 

 racters are comprehended in this extensive class. 

 In all, as their name imports, the body is of soft 



