500 A POPULAR EXPOSITION OF THE 
The Caterpillar is stated by Boisduval to feed on the Linaria 
Canadensis. It is black and spinous, with two lateral white lines, 
the upper of which is marked with a row of reddish spots.* 
London, C. W., August 13, 1861. 
A POPULAR EXPOSITION OF THE MINERALS AND 
GEOLOGY OF CANADA. . 
(Continued from page 455.) 
BY E. J. CHAPMAN, 
PROFESSOR OF MINERALOGY AND GEOLOGY IN UNIVERSITY COLLEGE, TORONTO, 
PART IV. 
SOME REMARKS ON ORGANIC REMAINS, WITH SPECIAL REFERENCE 
TO CANADIAN FORMS. 
Many stratified rocks, it has already been explained, contain the 
fossilized remains or impressions of vegetable and animal forms— 
vestiges of departed races of plants and animals which peopled the 
Earth and its waters during the epochs in which these rocks were 
under process of deposition. So numerous in some instances are the 
remains in question, that certain strata appear to be almost entirely 
made up of them, either in a perfect or in a fragmentary condition. 
The study of these fossils has a three-fold value: first, in enabling 
us to recognise one rock division from another, each division holding 
its own proper and separate forms; secondly, in elucidating obscure 
points in the structural and other relations of existing types; and 
thirdly, in shedding light upon many of the past conditions of the 
globe, both physical and organic. In illustration of the first of 
more practically useful character in connexion with these remains, it 
may be observed that in the great coal-bearing and all overlying 
* Since writing the above, Vanessa Czenia has been found in the townships of Ellis and 
Logan, about ten miles north of Stratford. From this it appears that its range is a more 
extensive one than I anticipated. The two places in which it has been found being some 
sixty miles or more apart, it is very probable that it will be met with in some spots inter- 
mediate. Since this Butterfly has undoubtedly been more prevalent than usual during the 
past season, it would be interesting to know to what extent it has prevailed in this section 
of country. I should be glad if collectors wonld communicate anything they know on the 
subject.—W. S. 
