1885.] NATURAL SCIENCES OP PHILADELPHIA. 1G7 



of karaes represents the portion of the glacier whose melting 

 supplied the kame streams. These small kames represented an 

 outward drainage. 



There are two curious little kames immediately south of 

 Ackermanville, in Washington Township, Northampton Count}', 

 which, though but miniature examples, have all the characters of 

 larger kames, and offer a suggestion as to their origin. 



Two small, straight, narrow ridges of stratified drift, 15 feet 

 high and about 100 feet long, may be seen just below the village, 

 running nearly at right-angles to the valley of the west branch 

 of Martin's Creek. Both of these ridges run from the base of a 

 hill west of the creek toward the stream, their direction being 

 south 75° east; and west of each of them there is an opening in 

 the hill, near the summit of which the moraine lies. 1 



Upon examining the structure of these ridges, as exposed by 

 transverse cuts made by the railroad, they are found to be com- 

 posed of fine stratified sand within and gravel without. The 

 sand shows flow-and-plunge stratification, with a distinct anti- 

 clinal structure. 



Here again the only satisfactory explanation is that they are 

 due to subglacial streams which drained the melting edge of the 

 glacier on the hillside backward into the subglacial valley, now 

 occupied by the west branch of Martin's Creek. They are here 

 at an elevation of 500 feet above the sea and about 190 feet below 

 the edge of the moraine and are beautiful examples of miniature 

 kames. An important point to note is that on placing the eye 

 along the crest of each of these they are seen to be opposite small 

 depressions in the hill on which the moraine rests. They are thus 

 in precisely the position that would be occupied by the natural 

 drainage of the edge of the ice-sheet. 



The most interesting of all the kames of Monroe County are 

 the curious conical hills and short ridges of sandy drift which lie 

 along the centre of Cheny Yalley, between the moraine and the 

 Delaware River. A remarkable series of conical hills of peculiar 

 and characteristic topography either stand singly, or (more gene- 

 rally) are connected one with another by irregular banks of 

 gravel, to form a series parallel with the valley. 



Near the Delaware Water Gap these hills rise often over 200 

 feet above the river, and often inclose basin-shaped depressions 



1 See sketch-map in Report Z, p. 34. 



