408 J. W. Dawson— Paleozoic Land Snails. 
was subsequently examined by M. Deshayes and Mr. Gwyn 
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 single 
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 speci- 
mens 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 
‘Paleeontology,’ subsequently proposed the generic name Den- 
dropupa. is ave 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 dis- 
tinction, 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 Pups. With regard to the 
form of its aperture, I may explain that some currency has 
been given to an incorrect representation of it, through an un- 
fortunate accident. In the case of delicate shells like this, 
im ed in a hard matrix, it is of course difficult to work out 
in my possession. This restoration, specimens subsequently 
pens 
The lowest bed in which Pupa vetusta occurs belongs 
group VIII of Division 4 of my section of the South Joggins, 
