498 FOSSIL INVERTEBRATED ANIMALS. 



these were a kind of stones which vegetated, or plants whose 

 tissue was solid, like that of stone. 



The second, or the corneous polyparia, have been named, 

 for a similar reason, ceratophytes (ks^ocs, a horn), supposing 

 that they were also plants, whose tissue had, more or less, rela- 

 tion with that of horn. 



The corticiferous polyparia are those which, either calca- 

 reous or corneous, are clothed, as their name implies, with a 

 sort of bark in which there are polypiferous compartments, as 

 in the isis, the corals, and the gorgons. 



As to the fibrous polyparia, which are also evidently corne- 

 ous, they have not received any particular denomination ; 

 they are, with little difference, the pasty or glued polyparia of 

 M. Lamarck. 



Finally, in contemplating the fleshy and contractile mass, 

 which constitutes the common part of the pennatulae, as a true 

 polyparium analogous to that which forms the alcyone, we 

 would have another species of polyparia, which might be 

 designated under the name of fleshy polyparia. 



Taking into consideration the solidity of the polyparia, they 

 have been again divided into those which are solid, not 

 flexible, and those which are flexible. By polyparia not 

 flexible are understood all those which, whether calcareous or 

 corneous, present a resistance more or less considerable ; and 

 by flexible polyparia, the different species into the texture of 

 which enters a greater or less quantity of fibrous tissue, which 

 permits this flexibility. 



But it is especially on the consideration of the forms of 

 the polyparia, that a greater number of subdivisions has been 

 established, such as arborescent or phytoid, frondescent, lamel- 

 lated, or lamelliferous^ for animated and vaginiform poly- 

 paria, &c. 



The composition of polyparia has likewise given rise to their 

 division into simple and compounded, or complex, polyparia. 



Finally, admitting the possible existence of polypi with free 



