1893.] Proceedings of Scientific Societies. 177 
rocks of Marylend, with a summary of the reasons for regarding them 
as eruptive in origin. Epidote as a Primary Component in Granites, 
Charles Rollin Keyes,!Des Moines, Ia. Occurrences of the mineral in 
certain granites regarded as eruptive described, the evidences of its 
original nature explained and its associations with the closely related 
Allanite considered. On the Laurentian of the Ottawa District, Rob- 
ert W. Ells, Ottawa, Ont. The paper briefly reviewed the work of 
the late Sir Wm. Logan in this district, forty years ago, and discussed 
the structure of the calcareous portion of the system, more partic- 
ularly as regards the relationship of the crystalline limestones to the 
underlying gneiss; with a brief statement of the several kinds of 
intrusive rocks which penetrate both the gneiss and limestone, and 
their apparent influence upon the occurrence of the economic minerals, 
such as graphite, apatite and mica. The Contact of the Laurentian 
and Huronian North of Lake Huron, Robert Bell, Ottawa, Ont. The 
line of contact between the Great Huronian Belt to the northward 
and the Laurentian area to the southward was traced from near Killar- 
ney on Lake Huron to its intersection with the Ottawa River. The 
two sets of rocks in this region were described with regard to their 
structure and their relations to one another. The nature of their con- 
tact here and in other instances in Canada was described in connection 
with the question of the conformability or otherwise of the two sys- 
tems. Reference was made to tl t linary develop tof quartzit 
in the LaCloche region, to certain forms resembling fossils lately dis- 
covered by the writer in the Huronian rocks of the vicinity, to the 
greenstone masses and dykes, to the nature of the granites and to other 
points in connection with the geology of the district. The marked 
dependence of the physical geography upon the phenomena of erys- 
talline rocks of the region was likewise pointed out. The Archean 
Rocks West of Lake Superior, W. H. C. Smith, Ottawa, Ont. (Intro- 
duced by R. W. Ells.) This paper gave a brief description of the 
rocks and their distribution between the Lake of the Woods and Lake 
Superior north of the International boundary and referred to some 
of the theories of origin and structure of the various members of the 
Archean system and to the iron orés and gold-bearing rocks of the 
region. On the Archean of Sudbury Mining District, Alfred E. 
Barlow, M. A., Geological Survey Department, Ottawa, Ont. This 
paper related in detail the various phenomena in connection with 
the contact between the Laurentian and Huronian to the northeast of 
Lake Huron, with a discussion of the origin and relative age of each, 
based on these observations. Notes on Cambrian Fossils from the 
