CLASS IV.— POLYPI. 



In this class there are tentacula, which surround the mouth. 

 Most of the genera propagate by off-shoots, as well as by eggs. 



It includes three orders, viz. — 



Class. Order. 



f Polypi carnosi. 

 Polypi . . \ Polypi gelatinosi. 

 V Polypi polypiferi. 



ORDER I.— Polypi Carnosk 



Called also fixed sea-nettles. They have a fleshy envelope, and 

 are generally fixed to some submarine object, but occasionally free. 



Genus. Subgenus. Example of Species. 



r 1. Actinia, prop Ac. senilis, L. 



AptiniT J ^' Thalassiantlius .... Tlial. aster, Ruppel. 



J 3. Discosoma D. nummiforme, Id. 



V. 4. Zoanthus Hydra sociata, Gm. 



Lucemaria L. quadricornis, Miill. 



ORDER II. — Polypi Gelatinosi. 



Are without any general envelope, and are gelatinous. Their 

 body represents a mere bag. 



Gemis. . Example of Species. 



Hydra, Lin H. viridis, Trembley. 



Corine, Gcertner. Tabularia coryna, Gm. 



Cristatella C. mucedo, Cuv. 



Vorticella 



Pedicellaria See Miiller, Zool. Dan. xvi. 



p 2 



