CLASSIFICATION. 75 



distinguished by a very remarkable dissimilarity of organi- 

 zation. These classes have been named Anthozoa and 

 PoLizoA, and may shortly characterized thus : — 

 Class I. Anthozoa. — Body tending to globular, contractile 

 in every part, symmetrical : mouth and vent one : gem- 

 miparous, and oviparous. 

 Class II. PoLYZOA. — Body elongate, syphonal, non-contrac- 

 tile, and unsymmetrical : mouth and anus separate : 

 oviparous. 



Class Anthozoa, Ehrenberg. 



The Anthozoa are divisible into the following orders : — 



I. Hydroida. — Pol2/pes compound, rarely single and naked 



the mouth encircled with roughish filiform tentacula 

 stomach without proper parietes ; intestine 0. ; anus 

 reproductive gemmules pullulating from the body and 

 naked, or contained in external vesicles. Polj/pidoms 

 horny, fistular, more or less phytoidal, external. 



II. AsTEROiDA. — Polypes compound, the mouth encircled 



with eight fringed tentacula; stomach membranous, 

 with dependent intestinal appendages ; intestine ; 

 anus ; ovules produced interiorly. Folype-mass vari- 

 able in form, free or permanently attached, carnose, 



