Chap. III.] 



ANTHOZOA. 



43 



an example of the 

 forms in which the 

 original mouth is lost, 

 and replaced by a 

 number of small aper- 

 tures developed on the 

 long arm - like out- 

 growths of its lips. 



B. Anthozoa. 

 Among the Anthozoa 

 we find the sea- 

 anemoiies and the great 

 bulk ol those cceleri- 

 terates which form 

 coral. 



According as they 

 possess eight, and eight 

 only, or six, or some 

 multiple (often a large 

 one) of six, we divide 

 the Anthozoa into the 

 Octactiniae, and the 

 HexactiiiisB. 



I. The Octactinise 

 have never more than 

 eight tentacles, and 

 these are flattened and 

 serrated at their edges. 

 In Alcyonium ("dead 

 men's fingers ") cal- 

 careous spicules are 

 scattered in the body ; 

 in Tubipora ("organ- 

 pipe coral") the spi- 

 cules collect and form 

 a continuous tube for 

 each polyp (Fig. 14 A) ; 



Fig. 14 B. Pennatula 

 (Pteroides) spinosa. 



