158 PROCEEDINGS OF THE ACADEMY OF [1885. 



showing distinct torrential action, and a coarse gravel on the 

 outside. Sometimes, but rarely, large boulders lie on top of the 

 kames. The writer has never observed large boulders within 

 them. The material is generally small, and well water-worn and 

 rounded, showing no glacial scratches on its pebbles, and for the 

 most part is of local origin. 



The contours of these kames in their " hummocky " appearance, 

 are very like those of moraines. Indeed, it is often impossible 

 to distinguish kames from moraines by external features alone. 

 When, however, we take into consideration their structure and 

 their position, they cannot readily be confounded. Their distin- 

 guishing characters are (1) their internal structure, kames being 

 distinguished by an absence of till and glaciated pebbles, and by 

 stratified, generally anticlinal, structure — all of these characters 

 being very different from the unstratified pell-mell character of 

 moraines ; (2) their geographical position and the influence of 

 the surrounding topography upon them. Topography has prac- 

 tically no influence on the moraine of the great glacier. The 

 terminal moraine on the Pocono plateau closely resembles that 

 in Cherry Valley, 1000 feet below it; and the moraine at the 

 height of 2500 feet, in central Pennsylvania, cannot be distin- 

 guished from that in New Jersey, at the sea-level. The moraine 

 may lie on the downward slope of a hill, as at Fishing Creek, 

 Columbia Co.; may form a dam across a creek, as at Cole's Mills, 

 or it may stretch transversely across a mountain ridge such as 

 the Kittatinny Mountain. 1 



On the other hand, kames as a rule depend directly upon topo- 

 graphy. While they do not always coincide with the present 

 drainage systems, they extend from higher to lower levels. They 

 follow valleys generally along the central line, but sometimes, 

 indeed, rising over considerable elevations. Where the valleys 

 are distinct and sharply defined by high ridges on either side, 

 the kames are confined to them, and follow more or less closely 

 the modern water-courses ; but where, as in southeastern Massa- 

 chusetts, the valleys are not w r ell marked, and there is no defining 

 wall, the country being nearly level or rolling, and there being 

 no mountain ranges, kames often cross where there are now no 



1 This independence of the terminal moraine as regards topography, is 

 prominently brought out in the detailed deseription of it given by the 

 writer in Report Z, Second Geological Survey of Pennsylvania. 



