64 The Ohio Naturalist. [Vol. VII, No. 4, 



further emphasizes this distinction in his contribution (Glacial 

 Phenomena of North America) to this volume. In defining 

 these he says of osars or eskers: "These terms are restricted to the 

 long, gravel ridges which conform, in general, to the direction of 

 the ice-movement, and which are thought to represent the main 

 drainage lines of the glaciers in their later stages, particularly 

 when they approach a stagnant condition. The term kames, 

 on the other hand, is applied to those gravel accumulations which 

 take on the form of bunchy aggregations of knolls and irregular 

 ridges, and have the tendency to arrange themselves in belts 

 parallel to the margin of the ice. They frequently accompany 

 terminal morains and have a quasi-morainic aspect." 



In his thorough work on "The Glacial Gravels of Maine," 

 under the head of " Sediments Transported by Glacial Streams," 

 Stone (^) states that: "The simplest form is that of a cone, dome 

 or hummock, and we find all transitions between these forms 

 and the elongated, two sided ridges." "These gravel deposits 

 have such curious and distinctive shapes that they have received 

 local names wherever they occur. The Scandinavian osars, the 

 Irish eskers (or eskars or eschars) and the Scottish kames are 

 supposed to be the equivalents of the gravel ridges here described, 

 or nearly related to them. These deposits contain matter of 

 various sizes from fine clay to large bowlders, but gravel is by 

 far the most abundant. I have found the term glacial gravel a 

 convenient general title for describing every kind of coarse sed- 

 imentary formation which was deposited by glacial streams. 

 The term has the disadvantage of implying a theory as to the 

 origin of these sediments, and it does not describe their compo- 

 sition in all cases, yet it is often convenient as a generic name 

 when there is doubt what specific name should be given to a cer- 

 tain deposit, whether kame, osar, etc." In chapter IV, "General 

 Description of the Systems of Glacial Gravel," the term osar is 

 exclusively used for these systems. These are described as com- 

 prising the sediments deposited by a single glacial river with its 

 tributary and delta branches. Stone, in Chapter VI, quotes. 

 Chamberlin's distinction between the osar or esker on the one 

 hand and kame on the other. He carries it a step further, how- 

 ever, and applies esker to the separate mounds and ridges of a 

 series of separated deposits known as a discontinuous osar. 



In his exhaustive works, "The Illinois Glacial Lobe" ('') and 

 " Glacial Formations and Drainage Features of the Erie and Ohio 

 Basins," C) Leverett uses exclusively the term esker for these 

 gravel ridges whose longitudinal axes correspond to the local 

 axis of the ice sheet. Whether intentionally or otherwise this 



4. Monograph XXXIV. U. S. G. S. p. 34. 

 ri. Monograph XXXVIII. U. S. G. S.. 1809. 

 6. Monograph XLI. U. S. G. S., 1902. 



