268 ZOOLOGY. 



11. Tubularia. Stem tubular, simple or branched, fi3s:ed by 

 the base ; animal proceeding from the extremity of the 

 tube, and having its head crested with tentacula. 



12. CoralUna. Coralline. Animal in form of r plant ; 

 stem fixed, with calcareous subdivided branches, mostly 

 jointed. 



13. Sertularia. Animal as the last ; 5few branched, pro- 

 ducing polypes from minlite cup-shaped cells. Of this 

 genus there are two families ; * stem horny, tubular, 

 affixed by the base, and furnished with vesicles or ova- 

 ries containing pdifpes^ ^SS^:/ ^^ living yvung ; ** 

 stem crustaceous, inclining to stone, composed of 

 rows of cells ; vesicles wanting, in lieu of which arc 

 small globules. 



14. Pennatula. Sea-Pen. Animal not affixed, of various 



shapes, supported internally by a bony substance, naked 

 at the base, the upper part with lateral ramifications ; 

 furnished with rows of tubular denticles, producing 

 ydiAv3iie polypes from each tube. 



15. Hydra. Polype. Animal affixing itself by its base, 



linear, gelatinous, naked, contractile, and furnished 

 with setaceous tentacula, inhabiting fresh waters, and 

 producing its deciduous offspring from its sides. 



