90 Scientific Intelligence. 



The Duck Mountain is shown to be of particular interest as its 

 summit is composed entirely of morainic debris, and after the 

 retreat of the continental glacier the summit of this moraine 

 became itself a collecting ground for the snow from which glaciers 

 flowed down the valleys of the surrounding slopes. A few kames 

 are also recorded as occurring along with this latest stage of 

 glaciation. 



Overlying the till throughout extensive areas are stratified 

 alluvial deposits that have been laid down in the beds of extinct 

 Post-glacial lakes. A marked feature of these beds is the absence 

 of fossils of any kind. The positions of some of these lakes is 

 indicated, one or more lying near the headwaters of the Saskatche- 

 wan River, one east of the Missouri Coteau, and one on the upper 

 Assiniboine, but the largest occupied the basin of Lake Winnipeg 

 and has been named by Mr. Warren TTpharn, Lake Agassiz. The 

 shores of this lake have been traced northward to lat. 53°, and 

 how much farther north they extend is not known. 



Mr. Tyrrell in answer to questions stated that the evidence at 

 present' at hand appeared to indicate that the preglacial drainage 

 of the Winnipeg basin was northward rather than southward, 

 and that the isolated bowlders seen on the surface of the plains 

 had probably been carried to their present position within the 

 ice of the glacier itself, and not beneath it, as had been the case 

 with the great mass of the till. 



2. 8th Annual Report of the Director of the U. S. Geological 

 Survey, 1886-87. — The following are Papers in this Report 

 issued separately. 



(1.) The Trenton Limestone as a source of Petroleum and 

 inflammable gas in Ohio and Indiana ; by Edward Ortost. 

 180 pp. — The Report of Prof. Orton is a full and thorough treat- 

 ment of the subject of petroleum and gas from the Trenton lime- 

 stone. The facts are among the marvelous in science, and they 

 are here ably presented and discussed both from a geological and. 

 economical point of view. Mr. Orton's paper in the last volume 

 of this Journal is in illustration of one branch of this subject. 



(2.) The Geographical Distribution of Fossil Plants ; by 

 Lester F. Ward. 300 pp. — Mr. Ward states in his opening 

 sentence that this paper is intended as a contribution to the 

 Sketch of Paleobotany which appeared in the Fifth U. S. G. S. 

 Annual Report. That paper was written as an introduction to a 

 larger work dealing exclusively with the literature of the science, 

 and proceeding primarily from a bibliographical standpoint. 

 This paper continues the subject " without departing from the 

 chiefly bibliographical method," while at the same time bearing 

 on the geographical distribution of fossil plants inasmuch as the 

 bibliography is presented under geographical divisions, com- 

 mencing with Great Britain. Mr. Ward makes the bibliography 

 historical for each country as regards the developments in paleo- 

 botany, gives copious notes on the various works mentioned, and 

 points out the bearing of discoveries in solving the various questions 



