358 J. D. Dana—Glacial Phenomena 
Map of Round Hill and vicinity, on the western border of the New Haven region- 
of till is at least 21 feet, as found in a well-digging. It is ec 
lengthened in the direction S. 10° W.: and only here is the 
; in tk a * The 
slope an even one—a fact represented in the map above. 
hill thus covers and fills the eastern half of this part of the 
Maltby Park valley. At its western foot flows Cove River, 
the stream of the valley. Across this stream, another ov 
immediately begins, that of one of the deeply till-covered bu : 
f southern Orange ; so that the Maltby Park valley is here fillec 
* It has the constitution, as the description shows, of the “ lenticular hills " of 
Professor Edward Hitchcock. But the quality lenticular is not an essential imi 
of such till-made hills, though common, as it is, and for a like reason, of many ° 
the rocky ledges of the same region 
