1 889-] Geology and PalcEontology. 151 
of what we now call the glacial epoch; though if the stratified 
rocks of the earth's crust consisted of old land-surfaces, instead 
of old sea-bottoms, traces of many glacial periods might be de- 
tected. The present land-surface will be entirely destroyed, 
in order to form the future sea-bottom. It is only those ob- 
jects which lie in existing sea-bottoms which will remain as 
monuments of the post-tertiary glacial epoch. It is then 
probable that the geologist of the future will find in the rocks 
formed out of the non-existing sea-bottom more evidence of a 
glacial epoch during post-tertiary times than we now do of 
one, say, during the Miocene, Eocene, or Permian period. 
Palaentology can afford but little reliable information as to the 
existence of former glacial periods. 
The Vertebrata of the Swift Current River, II. In 
the Naturalist for 1885, p. 163, the writer gave a brief ac- 
count of the vertebrata of the above locality obtained by the 
Geological Survey of the Dominion of Canada. Explorations 
set on foot by the Director of the Survey, Dr. A. R. C. Sel- 
wyn, during the year 1888, resulted in the obtaining of a num- 
ber of additional species, some of which are of considerable 
interest. In describing these, I will enumerate those already 
known from that locality. The specimens are generally in a 
fragmentary condition, owing to the conglomeritic nature of 
the deposit. The new material was obtained by Mr. T. C. 
Weston, of the Survey. The total number of species is seven- 
PlSCES. 
Aviia sp., numerous vertebra;. 
Reptilia. 
Trionyx sp., Ann. Report, G. N. H. Survey, Canada, 1885, 
c. p., 79. 
Stylemys sp. loc. cit. 
Mammalia. 
Rodentia. 
Palceolagus tiirgidus Cope, loc. cit. 
Bunotheria. 
Hemiopsaldon grandis Cope, loc. cit., and American JNat- 
uralist, 1885, p. 163. 
Ancylopoda. 
Chalicotherium bilobatum sp. nov. 
