Correspondence. 65 
On the structure of Monument mountain, Great Harrington, Massa- 
chusetts, T. Nelson Dale. l-lth Ann. Rept. U. S. G. S., pp. 551-505, 
pis. 71-72, 1895. 
The laccolitic mountain yroiips of Colorado, Utah and Arizona, 
AVliitman Cross. 14lh Ann. Kept. U. S. G. S., pp. 157-241, pis. 7-10. 
1895. 
Geolop'ical section — St. Louis to Shawneetown, J. M. Niekles. Final 
Report of the Illinois Board of World's FairCommission, pp. 155-223, 
1 pi., Sprin-itield, 1895. 
V. Proceedings of Scientific LdbiU'dtories, etc. 
Univ. of Cal., Bull. Dept. Gcol., vol. 1, no. lU. On lawsonile, a new 
rock-forminy mineral from tiu- Til)uroii peninsula, Marin Co., Cal., F. 
L. Ransome. Pi>. 301-:]12, pi. 17, May, 1895. 
CORRESPONDENCE. 
lNTERGLACi.\Ti Climatic Conditions. In the article by Mr. Warren 
Upham, printed in the May number of the Americ.\n GEOiiOoisT and 
entitled "Climatic Conditions shown by North American Interylacial 
Di'posits," it appears to me that tlic author very greatly underrates the 
evidences of a warm climate afforded by the plant remains found in th(! 
defjosits of this age in the vicinity of Toronto. The particular beds in 
wliieli liiese remains ha\c Ixmmi found at Toronto and Scarborough nuiy 
for 1 lie present be assumed to be contemporaneous, for, although liiis 
has not Ix'ci) absolutely proved, the evidence they give is at least con- 
current. 
In these beds the following si)ecies of |)lants have been recogni/.ed: (1) 
Aximina trilobit, (2) Fraxinu.'t qu(ulranyul<Ua, ('>) Querciis obtuxiloba, (4) 
JJlmusrecemosa, (5) TaxuHhaccaUtww. caiuideiiKi.t, {{S) Acer plei.'ttocenicum. 
Of these the yew (No. 5) is too wide si)read in habitat to give much in- 
formation, and the maple (No. (J) is supiK)sed io be a species now ex- 
tinct, but the four tirst-mentioned plants are all, for the region, south- 
ern forms, which here reach or surpass their present northern limits. 
This statement may be verified by consulting Prof. Sargent's "Forest 
Trees of North America" and Prof. Macoun's "Catalogue of Canadian 
Plants." Prof. Macoun, in fact, records the two tirst-named sjx'cies in 
Canada only from the shore of lake Erie: the third he recognizes doubt, 
fully in the southern part of Ontario, while the fourth is not ((uite so 
distinctively southern in habitat, being found sparsely both in southern 
Ontario and in the "Eastern Townships" of the province of t^)uebee. 
To assume, as Mr. Upham* doi's, tluit these trt-es llourishrd whrn 
"the ice-sheet was mell^'d away from tin; region of tin; l'i)per Lauren- 
tian lakes as far eastward as Toronto, while yet it remained on the 
*Loc. cit., p. 290. 
