32 PERMIAN EOSSILS. 



its generic collocation is therefore still a matter for further consideration ; and on the 

 same ground it is even doubtful whether it should be considered an Alcyonaria or a 

 Bryozoon. It is named after M. Voigt. whose ' Practische Gebirgskunde' contains some 

 account of the Permian beds of Germany. 



The specimen figured is attached to the exterior of a Prodiidus horridus found in 

 the Shell-limestone at Humbleton Uuarry, where it is rare. 



Sub-class CiLiOBRACHiATA, Farrc. 



PoLYZOA, /. V. Thompson. 

 Bryozoa, JEhrenberg. 



ZOOPHYTA ASCIDOIBA, JoTinstOU. 



Polypes Tuniciens, Milne Edwards. 



As previously stated, this group of Zoophytes does not appear to be divisible into 

 orders like the last sub-class, notwithstanding the attempts which have been made to 

 divide it by some naturalists. The divisions Infimdibidata and Hippocrepia proposed 

 by M. Gervais, as based chiefly on difference of habitat, whether marine or fresh-water, 

 appear so divested of the necessary structural individuality, and of so little value com- 

 pared with the orders already noticed, that in place of adopting them, it seems a much 

 safer plan to regard the Ciliobrachiates as resolvable into only one order, for which 

 Ehrenberg's name Bryozoa may be very conveniently retained. In this case the names 

 of M. Gervais may be advantageously used to distinguish groups of a lower value. 



The sub-class CiliobracJtiata comprises both marine and fresh-water productions. 

 The very minute Cristatellas and Plumatellas inhabiting ponds and lakes are of the 

 latter kind ; while the Flustras (Sea-mats), Escharas, Elasmoporas (Lace-coral), and 

 several others, represent the marine section. 



As some of the members of this sub-class form a highly interesting group of 

 Permian Zoophytes, I have been induced to give a short description of the polyps 

 inhabiting similar productions of the present seas. Referring to Plates II, IV, and V, 

 certain figures will be observed representing highly magnified parts of Fenestella and 

 other allied genera. These figures exhibit the stems, branches, and other parts, with 

 a number of circular openings (vide PI. II, figs. 9, 10, and 11 ; PI. IV, fig. 5 ; PI. V, 

 figs. 3, 9, 1 1, 12, &c.), which in the originals are so minute as to require a magnifier 

 to render them visible. Every opening is the entrance to a minute cell formerly 

 tenanted by a microscopic polyp, thousands of which constructed and cotenanted 

 such a Coral as is represented in Plate III, fig. 14. In giving a description of an 

 existing ciliobrachiate polyp and its cell, it is believed that it will serve to illustrate the 

 Corals hereafter to be described. 



The polyp is generally of the form of an elongated sac, which is protected for a 

 considerable extent inferiorly by a covering of a horny nature in Flustra, and of 



