454 THE CANADIAN NATURALIST. [Vol. ix, 



Jeffries, who concurred in this determination ; and its micro- 

 scopic structure was described by the late Prof. Quekett, of 

 London, as similar to that of modern land shells. The sioo-le 

 specimen obtained on this occasion was somewhat crushed and 

 did not show the aperture. Hence the hesitation as to its 

 nature, and the delay in naming it, though it was figured and 

 described in the paper above cited in 1852. Better specimens 

 showing the aperture were afterward obtained by the writer, 

 and it was named and described by him in his '' Air-breathers of 

 the Coal Period," in 1863. Prof. Owen, in his " Palseontology," 

 subsequently proposed the generic name Dendropupa. This I 

 have hesitated to accept, as expressing a generic distinction not 

 warranted by the facts ; but, should the shell be considered to 

 require a generic or sub-generic distinction, Owen's name should 

 be adopted for it. There seems,]^however, nothing to prevent it 

 from being placed in one of the modern sub-genera of simple- 

 lipped Pupas. With regard to the form of its aperture, I may 

 explain that some currency has been given to an incorrect repre- 

 sentation of it, through an unfortunate accident. In the case of 

 delicate shells like this, imbedded in a hard matrix, it is of 

 course difficult to work out the aperture perfectly ; and in my 

 published figure in the ''Air-breathers," I had to restore some- 

 what the broken specimens in my possession. This restoration, 

 specimens subsequently found have shown to be very exact. 

 Nevertheless it was criticised by some^English conehologists, and 

 when Sir Charles Lyell was about to publish his Student's 

 Manual, he asked me to give him one of my best specimens to 

 be figured. This I sent with micro-photographs of others. It 

 seems, however, that the artist or engraver mistook the form of 

 the aperture and gave it an entirely unnatural appearance in the 

 Student's Manual. That now given is taken from a photograph 

 of the most perfect Bud least compressed specimens in my pos- 

 session. 



As already stated, this shell seems closely allied to some 

 modern Pupae. Perhaps the modern species which approaches 

 most nearly to it in form, markings and size, is Macroclieilus 

 Gossei from the West Indies, specimens of which were sent to 

 me some years ago by Mr. Bland, of New York, with the re- 

 mark that they must be very near to my Carboniferous species. 

 Such edentulous species, as Pupa (^Leucochila) fcdlax of Eastern 

 America very closely resemble it ; and it was regarded by the 



