180 The American Naturalist. [February, 
high-level and low-level portions of the formation, beginning in South- 
ern Maryland and gradually increasing northward to New Jersey. A 
Geological Reconnoissance in the Central Part of the State of Wash- 
ington, Israel C. Russell, Ann Arbor, Mich. The region traversed 
embraces about 10,000 square miles in the arid region east of the cas- 
cades and drained by the Columbia. The reconnoisance was made for 
the purpose of learning how far the conditions there existing favor the 
project of obtaining artesian water for irrigation. The following is 
a syllabus of the paper. 
Geography of the region explored. 
Geological formations. 
Crystalline rocks. | 
Columbin toe } Tertiary. Glacial records, ) Pleistocene. 
ake Lewis, 
Geological structure. Existing lakes. Artesian water supply. 
The Abandoned Strands of Lake Warren, Andrew C. Lawson, 
' Berkeley, Cal. The strands of Lake Warren, on the north side of 
Lake Superior, up to an elevation of 1200 feet above sea-level are 
post-glacial. It was not an ice-dammed lake. There was an outlet 
northward corresponding to one of its higher stages. A post-glacial 
depression of Central Canada whereby the James Bay slope was covered 
with marine sediments to a present altitude of 450 feet above tide and 
only 150 miles distant from Lake Superior is correlated with the max- 
imum fullness of Lake Warren, and the subsequent uplift is correlated 
with its subsidence. The strand lines show no evidence of deforma- 
tion. In the absence of ice dams and of a gorge of permanent drain- 
age, the Level of Lake Warren could only have been lowered by 
epeirogenic depression along its southeastern margin, i. e., in the region 
south of Lakes Huron and Michigan, which depression is thus coeval — 
with the post-glacial uplift of central Canada. High terraces and 
beaches are known to extend along the north side of Lake Huron from 
Sault St. Marie eastward and they are reported on the high lands of 
the Peninsula of Ontario; so that Lake Warren must have been the 
greatest of the known Quaternary Lakes. Its area is roughly estima- 
ted at 150,000 square miles. The Importance of Photography in 
Illustrating Geological Structure, R. W. Ells, Ottawa, Ont. In con- 
nection with this paper was shown a series of large photographs by 
Topley, taken under the direction of the writer, showing more clearly 
the mode of occurrence of the apatite in the deposit of the Bucking- | 
ham and Lievre district, as well as the relations of the intrusive 
