262 TABULATE CORALS. 



tively trivial features. To the opinions expressed in the paper 

 just referred to I still adhere — in the sense, that is, that I still 

 think the conclusion which I had then reached the only one 

 justified by the information at that time published. Since that 

 time, however, I have had the opportunity of making a careful 

 microscopic examination of authentic Russian specimens of C. 

 radians, Fischer, the type of its genus, and I am now quite 

 satisfied as to its generic distinctness ; while a similarly minute 

 investigation of Monticidipora and its allies has convinced me 

 that here also we have to deal with a distinct generic type. 

 Lastly, as has been previously shown, I have had now the op- 

 portunity, in association with my friend Mr R. Etheridge, jun., 

 of examining authentic Australian specimens of Stenopora, 

 Lonsd., and have thus been able to show that this genus is one 

 quite distinct from either Chcstetes or Montictclipora, and, in 

 reality, referable to the Perforate group of the FavositidcB. 



The type, then, of the genus ChcEtetes, as here restricted, is 

 the C. radiatiSy Fischer, of the Carboniferous of Russia, and the 

 generic diagnosis previously given is founded upon an exami- 

 nation of the structural characters of this form. It has, how- 

 ever, been pointed out by Mr R. Etheridge, jun., and myself 

 (Journ. Linn. Soc, vol. xiii. p. 365, 1877) that the corals known 

 as Alveolites septosa, Flem., and A. depressa, Flem., are generi- 

 cally inseparable from ChcBtetes radians, Fischer ; and we have 

 further described another species {Chcstetes hypcrbore^ts), from 

 the Carboniferous rocks of Scotland, as possessing similar 

 generic characters. All the forms just mentioned are of Car- 

 boniferous age, and there are no published species of corals from 

 either older or younger deposits which can, in the meanwhile, 

 be certainly asserted to belong to the same genus. I may say, 

 however, that I have collected in the Devonian Limestone of 

 Gerolstein, in the Eifel, specimens of a coral which would ap- 

 pear to be congeneric with C. radians, Fischer. 



If we take the corals just mentioned as the only satisfactorily 

 identified species of Chtztetes, we find that the corallum is mas- 

 sive and usually irregularly hemispherical or pyriform in shape. 



