BOOK SECOND. 

 POLYPI. 



CLASSIFICATION. 



§ 24. 



The Polypi are either immovably fixed, or seated on a locomotive 

 foot. Their soft body is in part enveloped by a solid support, the 

 polypary. This last is often, for the most part, horny or calcareous ; and 

 by it numbers of these animals are united into greater or less groups. The 

 central mouth is always surrounded by a coronet of contractile tentacles. 

 The digestive apparatus is organized after two different types, upon which 

 is based a division of these animals into two orders. The sexual appara- 

 tus is always without copulatory organs. 



ORDER I. ANTHOZOA. 



The digestive canal is without an anus, and opens into the general 

 cavity of the body. 



Family : Madreporina. 



Genera : Ocidina, Millepora, Madrepora, Caryophyllia, Astraea, Besmo- 

 phyllum, Maeandrma, Wlonticularia, Agaricia, Favia. 



Family : Gorqonina. 

 Genus : Gorgmiia. 



Family : Isidea. 



Genera : Corallium, Isis. 



Family: Tubiporina. 



Genus : Tuhipora. 



Family : Alcyonina. 

 Genera : Alcyonium, Lobvlaria, Alcyonidium. 



Family : Pennatulina. 

 Genera: Veretillum, Pennatula, Virgidaria. 



