88 . III. DIST. CHAR. Prototype. 



b, 65. FABRICATED ANIMAL P. (Paries animal '. 

 fabricates ) are parts superadded to the body by some 

 voluntary ? effort of the animal. These are shells 

 slid fulciments. 



SHELLS are hard, calcareous^ moveable coverings, 

 formed by an external apposition of matter, f se- 

 creted by the inclosed animal. 



Shells are peculiar to certain genera of vermes. 

 In respect to their general structure, shells are ei- 

 ther multivalves, bivalves, or univalves.^ 



FuLCiMENTsfff are immoveable, calcareous or 

 membranaceous props or supports, formed, also, by 

 an apposition of matter, secreted by different species 

 of zoophytes, fttf Fulciments are always fixed by 

 the base to some other body, from which they are 

 extended in various forms, more or less plant-like. 



In structure, fulciments are solid or cellular The 

 solid, when recent, are internal, being surrounded by 

 the zoophytes which fabricate them the cellular 



f Vide page 47. note f- 



tt For an explanation of these and other terms, see the end of 

 tin's section. 



fit We have adopted this term as a general one, to distinguish 

 all plant-like bodies formed by the Zoophyta, as habitations or sup- 

 ports; and which, according to their consistence, are denominated 

 coral, coralline, sponge, &c. 



fttt Fulciments are not innate bodies, although essential to the 

 existence of the worms they support. Like shells, they are gradu- 

 ally produced by a deposition of calcareous and jnembranaqeous 

 matter, exuded bv the animal inhabitants. 



