200 The American Geologist. September, idol 
to. Their demonstration of the grading- of the schists into 
igneous rocks of various kinds is' very important, and such 
gradation can hardly further be questioned by geologists. 
Whether such igneous rocks (granite, gneiss, dioryte, svcnyte) 
originated in situ from pre-existing rocks, mostly detrital, or 
are derived dc prufoiuiciir. entirely strangers to the rocks that 
they are now in contact with, is a problem that remains to be 
solved for the Archean of the Alps. n. h. w. 
MONTHLY AUTHOR'S CATALOGUE 
OF AMERICAN GEOLOGICAL LITERATURE 
ARRANGED ALPHABETICALLY. 
Ami, H. M. 
Billings and his InbJiography (Am. Geol., vol. 28, p. 132. Aug. 
1901.) 
Ami, H. H. 
Bibliography of Dr. George M. Dawson. (Am. Geol., vol. 28, pp. 
76-86. Aug., 1901.) 
Bain, J. W. 
The iron belt on lake Michigan. (Rep. Bur. Mines, 1901, pp. 212- 
214. Toronto, 1901.) 
Boyd, D. W. 
Michipicoten Mining Division. (Rep. Bur. Mines, 1901. pp. 137- 
144, Toronto, igoi.) 
Bow, J. H. 
Mines of Northwest Ontario: Part I. (Rep. Bur. Mines. 1901. pp. 
69-90. Toronto. 1901.) 
Carter, W.E. H. 
Mines of Northwest Ontario. Part H. (Rep. Bur. Mines. 1901. pp. 
go- 1 12. Toronto, igoi.) 
Chester, A. H. 
Mineral notes and explorations. (Ann. Rep. State Geologist, N. J., 
igoo. pp. 175-188.) 
Coleman, A. P. 
The Vermilion River placers. (Rep. Bur. A-Iines, 1901. pp. 151-159. 
Toronto, 1901.) 
Coleman, A. P. 
Iron ranges of -the Lower Huronian. (Rep. Bur. Mines. 1901. pp. 
1 81 -212. Toronto, 1901. 
Coleman, A. P. 
Glacial and interglacial beds near Toronto. (Jour. Geol., vol. 9, 
May— June, 1501. pp. 285-310. 
Coleman, A. P. 
Notes on Pleistocene Geology. (Rep. Bur. Mines, igoi. pp. 210- 
212. Toronto, 1901.) 
