138 The American Geologist. September, i.;o5 
north-flowing streams are in deep and wide pre-Glacial val- 
leys (these are shown by the topographic sheets), while 
the extinct channels are cut across the tops of the inter- 
valley ridges and high above the north-south valleys. In 
other words, the highest of them have both ends in the air. 
As the crests of the ridges decline 6r fall away to the north, 
the transverse channels on any meridian were cut success- 
ively from south to north, as the ice barrier receded, and of 
course at successively lower levels. As no channel was 
deserted until a lower escape was opened, it follows that 
each successive or lower channel must have been initiated 
at an altitude below the bottom of the preceding channel. 
The Syracuse channels and cataracts were functionally 
the predecessors of Niagara, as they carried the overflow 
of western waters eastward to the Ontarian level. Two of 
the fossil cataracts, those of Jamesville and Blue lakes, are 
comparable in hight and capacity to the present Niagara. 
No visitor, standing for the first time on the crest of the 
Jamesville lake amphitheater and appreciating the romantic 
history involved in the phenomena, will regret a journey of 
a thousand miles to view the region. (See plate vi. 
A brief description of these features, with illustrations, 
may be found in No. 3 of the references. 
The rivers which excavated the cross-ridge channels 
dumped their detritus into the valley lakes. A very prom- 
inent delta lies two miles south of Marcellus, in the Otisco 
valley, but this is beyond the easy reach of the excursions. 
It may be seen on the Skaneateles sheet. The largest delta 
in the region is in the Onondaga valley at the junction of 
the M'arcellus-Cedarvale channel, and shows on the Tully 
sheet. It can be reached on the trips and can be plainly 
seen miles away, from the east side of the Onondaga valley. 
This great delta extends from a mile northwest of South 
Onondaga around the north of Indian Village, a stretch of 
four miles. Another delta lies west of Jamesville at the 
mouth of the gorge, below the lake and ancient cataract. 
Still another and more conspicuous delta occurs at High 
Bridge in the limestone valley at the mouth of the White 
lake channel, and is mapped in the southeast corner of the 
Svracuse sheet. Small terraces and benches of stream detri- 
