LETTER XXVI. 



OPINIONS AND DISCOVERIES RESPECTING THE LIVING ANALOGUES 



OF THE PENTACRINITES. 



THOSE who admitted the presence of animal life in the recent ana- 

 logue of the pentacrinite, divided themselves into the supporters of 

 two opinions. The one considered the whole of the encrinus, or pen- 

 tacrinus, as belonging to a single individual animal, and place the 

 mouth in the centre of the base of the pelvis^ supposing the rays 

 which are disposed round the pelvis, to be so many arms which are 

 used by the animal to convey its food to its mouth, and the projecting 

 parts proceeding from the little cavities in the vertebrae as the instru- 

 ments of motion. The others consider this body as a mass of as 

 many separate polypes as there are articulations. The learned Hofer 

 adopted the latter opinion, in his Tentamen de Polyperitis * He re- 

 presents the formation of such an assemblage of polypes, to which, 

 when it has become a subject of the fossil kingdom, we give the name 

 of Encrinite, to take place in the following manner. When one of 

 these polypes, clothed with its testaceous covering, happens to be torn, 

 and separated from those to which it was united, the waves drive it 

 from one side to another, until it happens to fix itself by its arms to 



* Act. Helvet, Tome IV. p. 182, 



