SUBDIVISIONS. 95 



ture oi Fistulipora Canadensis, Bill, (so called), show, as above 

 noted, that Fishilipora, M'Coy, cannot be iclentical with Callo- 

 pora, Hall. I would remark, however, that Dr Steinmann's 

 conclusions on the above points are rendered nugatory by 

 the following considerations : In the first place, the fype of 

 the genus Fishdipoj^a, M'Coy, is the F. minor, M'Coy, ot 

 the Carboniferous rocks of Britain, and not the (so-called) 

 F. Canadensis of Billings. In determining, therefore, the re- 

 lations which subsist between Fishdipora, M'Coy, and CaUo- 

 pora, Hall, the only evidence of any value is that afforded by 

 F. minor, M'Coy, which is the type of the former genus ; and 

 it would not matter In the least what might be the structure of 

 the subsequently described F. Canadensis, Billings. I must, 

 thus, begin by denying that any evidence based upon the 

 structure of F. Canadensis, Bill, could have any bearing upon 

 the question as to whether Fistulipora, M'Coy, Is the same as 

 CaUopora, Hall. In the second place, the figure given by Dr 

 Steinmann as an enlarged drawing of a cross-section of the so- 

 called Fisttdipora Canadensis, Bill., Is seemingly not a drawing 

 of this species at all, but is apparently referable to some en- 

 tirely different type (perhaps either a Monticidipora or a Steno- 

 pora). I do not pretend to know what form is actually repre- 

 sented in the figure given by Dr Steinmann ; but I think it may 

 be safely asserted that it Is not the so-called Fistidipora Cana- 

 densis, Bill., or even apparently allied to It. I have a very 

 large number of specimens of F. Canadensis, Bill., which I 

 personally collected from the Devonian formation of Canada, 

 and I have made many sections of these ; and in confirmation 

 of the above statement it will be quite sufficient to direct 

 attention to the foregoing engraving representing enlarge- 

 ments of tangential and vertical sections of undoubted ^ ex- 

 amples of this species. An examination of these sections will 



^ In order that no doubt should exist as to the identity of my specimens with F. 

 Canadensis, Bill., I have in figs. A and b purposely chosen sections from a specimen 

 from the Corniferous Limestone which Mr Billings himself named and gave to 

 me; though the specimens I collected myself are, of course, just the same. 



