W. UM. Davis—Beerafts Mountain. 387 
stone conglomerate apparently at our locality F with the Cal- 
area. While the drawings cannot claim close accuracy, they 
made on rocks, roads and streams. The sections are plac 
directly where they belong on the map, as more seems to be 
gained by showing them in their true positions than is lost b 
breaking the continuity of the map surface. The Helderberg 
rocks are constructed in their probable position underground, 
but the Hudson River strata are shown only at their outcrops. 
limestone called ‘Corniferous’ is so name 
cherty and lies on the Cauda-galli shales ; but the identification 
is very probably correct. The Hudson branch of the Boston 
and Albany railroad passes a little distance northeast of the 
map, within clear view of the Lower Pentamerus bluffs. 
The relations of the Lower Helderberg to the Hudson River 
i iar 1 ion with the occur- 
n the full series of 
. 
Silurian deposits is represented, the two groups In question are 
separated by several intermediate formations—the Oneida, 
only by a few feet of transition deposits, all the strata being 
horizontal; the junction here has always been described as 
conformable, in spite of the long time that passed without 
deposing its record. Whether the actual contact has been 
