Febbuaby 20, 1903.] 



SCIENCE. 



299 



tinental slope, to oceanic depths. Chesa- 

 peake and Delaware valleys are buried on 

 the subcoastal plains, but reappear in 

 cirques at their margin, and can be traced 

 to 60 miles down the continental slope, 

 where they enter a deep embayment, like 

 the Hudson. The valleys of the Gulfs of 

 Maine and St. Lawrence, and smaller ones, 

 are traced across the subcoastal plains into 

 conspicuous amphitheatres in the edge 

 of the continental shelf, and these widen 

 out into embayments indenting the great 

 slope to oceanic depths. The continuation 

 of the deep fjords of Newfoundland are 

 obstructed, supposedly by drift, in crossing 

 the coastal plain, but this is in agreement 

 with the fact that the Lafayette formation 

 is older than the great valley-making epoch, 

 but the Columbia formation was subse- 

 quent to it. 



So also the remarkable deep cirques in 

 the far North Atlantic were described. 



The author considers these features, 

 which have their analogies on the margins 

 of the Mexican tablelands, as having been 

 finally fashioned by atmospheric agents, in 

 which case they become evidence of great 

 continental elevation about the beginning 

 of the Pleistocene period. The paper was 

 admirably illustrated by a series of maps. 



Geology of the Leucite Hills, Wyo. : W. C. 



Knight, Laramie, Wyo., and J. F. 



Kemp, New York city. 



The petrography of the Leucite Hills has 

 already been quite fully treated, but the 

 geological relations have been hardly 

 touched. The latter furnish the most im- 

 portant part of the paper, but petrographic 

 details are not neglected. Up to date six 

 separate exposures have been partially de- 

 scribed. The authors have located and 

 mapped twenty-two. The maps thus far 

 prepared are incomplete and inaccurate. 

 The authors have surveyed one which ex- 



presses the true relations much more faith- 

 fully. Surface flows, dikes, volcanic necks 

 and at least one probable intruded sheet 

 were described. The stratigraphical rela- 

 tionships, the probable time of intrusion 

 and the dissection of the mesas were treated 

 in closing, and it was shown that the out- 

 breaks probably occurred in the late Ter- 

 tiary. In discussion G. K. Gilbert re- 

 marked the probable derivation of the 

 sheets and dikes from a parent magma, and 

 the illustrations which they afforded of the 

 succession of closely related eruptions from 

 one source. Bailey Willis likewise com- 

 mented on the probability of the existence 

 of a great laccolithic reservoir beneath the 

 surface. 



The Work of the Geological Survey of Can- 

 ada in 1902 : Robert Bell, Ottawa, Can- 

 ada. 



The paper discussed the following top- 

 ics: The different classes of workers, their 

 numbers. Field-work; the parties which 

 were sent out, objects to be attained, means 

 employed; regions surveyed and explored 

 from the Yukon District to Nova Scotia; 

 some of the results. Work relating to 

 mines and economic 'geology ; to chemistry, 

 mineralogy and petrography; the publica- 

 tion of serial reports and special treatises, 

 with illustrations; artists' work; labors of 

 the staff in paleontology, zoology, eco- 

 nomic botany, fruit growing. The exten- 

 sion of agriculture in the north, forestry, 

 forest fires, preservation of timber; neces- 

 sity for topographical surveying in unex- 

 plored regions ; the compilation and engrav- 

 ing of maps, those published and those in 

 course of preparation during the year; 

 making of illustrative models of sections 

 and surface relief ; work in connection with 

 the museum and library; aid given to edu- 

 cation, distribution of reports, maps, 

 suites of named specimens of minerals and 



