234 ROCHESTER ACADEMY OF SCIENCE. 



revealed, very often in their minor details, the way in which they 

 were formed. The relation they bear to moraines, their relations at 

 the point of origin, their occurrence between the drumlins, the pres- 

 ence of lakes or swamps on either side, their composition largely of 

 gravel, their relation to kames, the local character of their materials, 

 the presence of till and large boulders on their surfaces, and of 

 kettles depressed into their crests, their occurrence in trenches in the 

 till sheet, their chaotic stratification, all seem to indicate a subglacial 

 origin for the Rochester eskers. 



While the preceding descriptions aim to include all of the eskers 

 near Rochester, New York, very possibly some occurrences have 

 been overlooked. Eskers of inferior dimensions are very likely to 

 be missed. One such occurs two miles northwest of Scottsville. It 

 is but a few hundred yards in length, 10 to 15 feet high, and lies 

 between two high drumlins, with swampy ground on either hand. 

 The topographic map (Rochester quadrangle) gives no indication 

 of it and as it occurs some distance from the highway it might be 

 very readily overlooked. Probably there are a number of such 

 isolated examples of eskers in the area under consideration which 

 are not high enough to be indicated on the topographic maps and the 

 occurrence of which is not known to the scientific public. 



Bibliography. 



1. L. Agassiz : Glacial phenomena in ]Maine : Geol. Sketches, 1876, p. 101 ; 



Atlantic Monthly, XIX, Feb. 1876. 



2. Baily: Historical sketches of Andover, Mass., 1880, pp. 19-24. 



3. E. Blackwelder and H. H. Barrows : Elements of Geology, pp. 228-229. 



4. T. T. Bouve: Geology of Hingham, Mass. 



5. : Kame ridges, kettle-holes, and other phenomena attendant 



upon the passing away of the great ice-sheet in Hingham, Mass. : 

 Proc. Boston Soc. Nat. Hist, Vol. XXV, 1890-92, pp. 173-183. 



6. A. P. Brigham : Text-Book of Geology, pp. 266-270. 



7. Fraxk Carney : The Pleistocene geology of the Moravia quadrangle, 



New York: Bull. Sci. Lab. Denison Univ., Vol. XIV, 1909, pp. 

 394-404. 



8. T. C. Chamberlin : The horizon of drumlin, osar and kame formation: 



Jour. Geol., Vol. I, pp. 255-267. 



9. : Recent glacial studies in Greenland: Bull. Geol. Soc. Am., 



\^ol. VI, pp. 215-216. 



