ON THE CARBONIFEROUS POLYZOA. 85 



peculiar biserial cells appeared like an analogous structure referred to 

 by Prof. Nicholson when describing Carinopora HimJei, Nich.' His 

 figures, however, are said to be transverse ; mine are longitudinal, or in a 

 line with the bases of the cells. These tail-like processes are constant 

 characters at certain intervals in my very small section, and the figures 

 given may help in the recognition of the genus in sections of limestone. 

 At first sight Archceopora has the appearance of Gallopora incrassata, as 

 described and figured by Nicholson, ^ but a vei-y little examination will 

 show the difference between the two forms, whereas one is a Polyzoa and 

 the other a Tabulate coral. 



I have now gone over the whole of the recorded genera and species 

 of British Carboniferous Polyzoa, with the exception of the Fenestellidm. 

 These having been so lately and so ably reviewed by Mr. Gr. W. Shrubsole, 

 F.G.S., their omission from this report will not be so much felt as the 

 omission of any of the other lesser known forms. Mr. Shrubsole, 

 after very elaborate investigations, and after the careful comparison of 

 nearly all the known so-called species, is inclined to restrict the twenty- 

 six species to five typical ones, namely^ : — 

 Fenestella plebeia — M'Coy 

 „ crassa ,, 



„ polyporata — Phillips 



„ nodulosa ,, 



„ membranacea 



all the other ' species ' falling into the rank of synonyms of one or other 

 of the five here received by him. But this does not confine the number 

 of known species to five. When his labours on the family are completed 

 several new forms will be described, together with at least two more 

 species of Pohjpora — the results of laborious investigations in North 

 Wales. There are also some references to the Polyzoa of the Carboni- 

 ferous Limestone of the districts between Llanymynech and Minera, 

 N. W., in the lately published work'' of G. H. Morton, F.G.S., Hon. Sec. 

 of the Liverpool Geological Society. 



Several other papers on special points, having reference to Polyzoa, 

 have been published during the last ten or twelve years. The vexed 

 question as to the Hydrozoal or Polyzoal affinities of Palceocoryne has 

 been debated by Prof. Duncan,^ Prof. Young, and Mr. John Young,^ and 

 by myself; ^ but the question as to their real affinities is still an open one. 

 Another paper by Mr. A. W. Waters,* entitled ' Remarks on some Fenes- 

 fellidce,^ contains some debatable matter, and the papers of Mr. Robert 

 Etheridge, Jun., on the genus GJauconome, Messrs. Young on the genus 

 Ceriopora, and the paper on the ' Perfect Condition of the Cell-pores and 

 other points of structure,' ° are valuable additions to our knowledge of 

 Carboniferous Polyzoa. Before any attempt can be made to construct 

 a system of classification which will embrace — naturally — the several 

 genera of the Palaeozoic Polyzoa, many, at present, very doubtful points 



' AnnaU and Mm/. Nat. Hist. Feb. 1S74, p. 81, figs, f and i. 

 - New Devonian Fos., Geo. Ma//., vol. i. 1874, page 2, plate 1. 

 ^ ^ ' Carboniferous Fenestellidse,' Q>ia7\ Join: Geo. Soc, May 1879. 



< The Cavb. Limestone and Cefn-y-fcdm Sandstone. London, David Bogue, 1880. 



=5 Phil. Transac, 1869. Jour, of Geo. ,Soe., 1873. Jour, of Geo. Soc, Dec. 1874. 



» Jour, of Geo. Soc, Dec. 1874. 



' Science Gossip, 1879. 



' Proc. of Manchester Geo. Soc., 1879. 



" Newspaper Report, Oct. 9, 1879. 



