14 
river does not come within the scope of this report, but the new variety 
was worked out while studying the genus Melania, and it was thought best 
not to leave it undescribed. 
The upper whorls of the variety have the ordinary appearance of the 
type, but in the lower whorls the transverse ribs have become almost 
obsolete. The revolving ridges are also not continuous, but well-developed 
nodes are present where the discontinuous ridges and the nearly obsolete 
transverse ribs cross. The result is a regular pattern of nodes over the 
whole whorl; these nodes are not circular or spiny, but are comparatively 
low and noticeably drawn out in the direction of the spiral ridge. In 
size and shape it is typical of M. whiteavesi. 
Horizon and Locality. Brosseau (Ribstone Creek) formation, North 
Saskatchewan river above Saddle Lake creek, sec. 8, tp. 37, range 12, W. 
4th mer. 
Pupa sp. indet. 
Plate III, figure 13 
At Nobleford, Alberta, in the St. Mary River formation, one specimen 
of a gasteropod was found which should, undoubtedly, be referred to the 
air-breathing genus Pupa. It will very likely prove to be a new species, 
but as it is incomplete, it was thought best to leave the detailed description 
until more specimens are found. It is somewhat similar to Pupa ata- 
vuncula White^ from the Upper Green River formation (Eocene), but is 
much larger and shows many minor differences. 
‘White, C. A.: U.S. Geol. Surv., Terr., Wyoming and Idaho, Con. Invert. Pal., pp. 46-47, PI. 19, fig. 9 (1878). 
