Notices of Memoirs — G. R. Vine on Fossil Polyzoa. 471 



anthracitic. Specimens of the overlying strata were selected from 

 the two districts at each foot above the coal for five feet; these 

 were analyzed, and it was found that the beds from near Cardiff 

 were considerably more argillaceous and, as a whole, less ferruginous, 

 than those at Aberdai'e. It would be rash to attempt to determine the 

 exact chemical nature of the sediment deposited over the coal-forming 

 vegetation in the two localities, as, with the exception of silicate of 

 alumina, the silicates and other minerals would have undergone de- 

 composition at the expense of the carbonic acid given off from the 

 coal-forming vegetation. There was, however, a decided change in 

 the beds of the two sections presented, which could not be ascribed 

 to metamorphisra. It rather appeared to point to the sediment 

 containing different constituents, which must have had a very con- 

 siderable effect on the vegetable mass. It was to this that the author 

 was inclined to assign the change in the character of the coal. 



VTII. — Second Eeport of the Committee, consisting of Prof. 

 P. M. Duncan and Mr. G. R. Vine, appointed for the purpose 

 of reporting on Fossil Polyzoa. Drawn up by Mr. Vine 

 (Secretary). 



AFTER many laborious researches, naturalists, generally, have 

 accepted Dr. Allman's Gymnolcemata, for one at least of the 

 orders of the Class Polyzoa. In this order the "Polypide is destitute 

 of an epistome (foot) : and the lophophore is circular." ' The order 

 is divided into three sub-orders : — 



I. Cheilostomata, Busk. = Celleporina, Ehrenberg. 

 II. Cydostomata, „ = Tubuliporina, Milue-Ed., Hagenow, Johnston. 

 III. Ctenostomata, ,, 



The whole were " founded by Professor Busk on certain structural 

 peculiarities of the cell."^ Only species belonging to two of these 

 sub-orders are found fossil, and to these alone i shall direct the 

 attention of the reader. 



I. Cheilostomata. — Polyzoa belonging to this sub-order are ''dis- 

 tinguished by the presence of a moveable opercular valve "^ This, 

 however, is not a character on which the Paleeontologist can rely for 

 evidence ; but there are others. The ova are usually matured in 

 external " marsupige," or ova cells ; there are also appendicular 

 organs — avicnlaria and vibricula ; and later investigations have 

 proved the existence of peculiar perforations in the cell-walls, which 

 Reichert called " Rosettenplatten," and Hincks " communication - 

 pores." Through these openings the "endosarcal" cord of Joilet,* 

 in the living Polyzoa, passed from cell to cell. The aperture, or 

 mouth of the cell, though variously shaped, is always sub-terminal. 

 To prove that Polyzoa (judging from the calcareous remains of this 

 sub-order)' were present in the Palseozoic seas, it is necessary that 

 some one or other of the above-named characters should be present 

 in the species introduced as Cheilostomatous. 



1 Hincks's Brit. Marine Polyzoa, p. cxxxvi. * Ihid. p. cxxiv. 



3 "Corneous," Waters on the use of the Operciila. Proceedings of Manchester 

 Lit. and Phil. Soc, 1878. (Italics mine.) 



** Nervous tissue, Miiller. 



