No, 8.J J. W. DAWSON — PALEOZOIC LAND SNAILS. 451 



long to the genus Fapa in its wider sense, and are very near to 

 sub-generic types still represented on the Anierican continent 

 and its islands. One is a small helicoid shell not separable 

 from the modern genus Zonifes, and the remaining one, though 

 it has been placed in a new genus, is very near some small 

 American snails of the present day (^Sfenotrema, etc.) All the 

 species are of small size, though not smaller than some modern 

 shells of the same types. 



I shall now proceed to give the characters and descriptions of 

 the several species, adding to the account of those previously 

 known, such new facts as have occurred in my more recent ex- 

 plorations and examinations. I should state here that many of 

 the new facts detailed have been obtained in the course of 

 excavations for extraction of erect trees holding land animals, 

 undertaken with the aid of a grant from the Government fund 

 for aiding original researches, at the disposal of the Royal Society 

 of London, and carried on within the past three years. 



1. Pupa vetusta Dawson. (Figs 1 to 4, and 14, a, h.) 



[Sir C. Lyell and Dr. Dawson on Remains of Reptiles and a Land 

 Shell from the South Joggins in Nova Scotia, Journal of G-eological 

 Society of London, a'oI. ix, 1832 (figured but not named). Dawson's 

 Acadian Geology, 1855, p. 160. Dawson's Air-breathers of the Coal 

 Period, 1863. Acadian Geology, 2nd and 3rd editions, p. 384, 1868 and 

 1879.] 



DescrijJtlon. — Shell cylindrical, somewhat abruptly conical at 

 the apex, in some specimens tending to diminish in diameter in 

 the latter turns or whorls of the shell. Whorls nine in adult 

 shells, slightly convex, in width equal to half the diameter of 

 the shell. Suture impressed. Aperture evenly rounded, not 

 continuous above, rather longer than broad, destitute of teeth ; 

 peristome slightly reflected and smooth. Surface shining, marked 

 with longitudinal smooth ridges, separated by spaces a little 

 wider than the ridges ; spaces about ^-J-^th inch in width. 

 Shell calcareous, thin, prismatic in structure. Young specimens 

 abruptly conical and helicoid in form. Nucleus round, smooth, 

 the first turn below the nucleus marked with rows of little 

 pits which gradually pass into the continuous striae. The last 

 whorl of the adult presents irregular lines of growth instead 

 of the regular microscopie ribs of the middle turns. Mature 

 ovum membranous, or so slightly calcareous that it can be com- 

 pressed without breaking : the embryo shell sometimes visible 



