ZOANTHARIA. 159 



described by many travellers. The upper portion of the body of the 

 animal, corresponding to the lamelliform part of the polypus, is fur- 

 nished with scattered tentacula, very long in some species, and re- 

 markably short in others. These tentacula appear to terminate in a 

 small sucker, and the animal seems to recover its position with difficulty, 

 when overturned. In order to complete our description of these 

 curious madrepores, we may refer to Fungia agariciformis, repre- 

 sented in Fig. 73. This remarkable species inhabits the Red Sea and 

 the Indian Ocean, and is here represented with its polyps. 



De Blainville gave the name of MADEEPOK^EA to the second group of 

 his stony Zoantharia, placing them after the Madrephyllise. The pro- 

 ducts of this section are generally arborescent, with small, partially 

 lamelliform cells, which are constantly porous in the interstices of the 

 walls of the cells, this being its most important characteristic. Thus 

 the visceral apparatus constitutes the essential part of the polypus, 

 presenting no side plates, the visceral chamber being open from the 

 base to the summit, and neither filled with dissepiments, pulpy matter, 

 nor with plates. 



The history of these inhabitants of the deep is extremely obscure, 

 and will probably always remain so ; the most beautiful of their pro- 

 ductions are intertropical, and consequently beyond the reach of dis- 

 criminating observers during the life of the animal. Solander proposed 

 to divide the genus according to certain characteristics in the growth 

 of the coral, and De Blainville has rearranged the groups formed by 

 Lamarck, Lamouroux, and Groldfuss, with special reference to the soft 

 parts of the animals figured by Lesueur, Quoy, Gaimard, and others, 

 who have observed them in their native state. 



The perforated Zoantharia form three very natural families : the 

 Eupsammidtz, the Madreporidse, and the Poriiidse. The first have 

 the solid parts of the polyps, simple or complex, with well-developed 

 lamellar portions, the central column spongious, walls granular, semi- 

 ribbed, and perforated. The second are composite, increasing by 

 gemmation; walls spongy and porous; septa lamellous, and well 

 developed. In the third the visceral chambers are divided into two 

 equal parts by the principal septa, which are more developed than the 

 others, meeting by their inner edge. The Dendrophyllide (Fig. 74) 

 are conspicuous among the Eupsammidse. 



