296 GEOLOGY AND MINERALOGY. 
Of the Corniferous limestone I found but one regular outcrop, occurring imme- 
diately above the Oriskany sandstone formation, and forming unmistakeably, 
therefore, the base of the formation. This exposure is about the eighth of a mile 
in width, and extends north-west into the township of Burford, (where it 
immediately disappears), and south-east into the township of Townsend. The 
northern edge of this exposure, consisting of a few thin strata, is no doubt in its 
proper situation, while the remaining portions have been broken and dragged 
from their original position by the powerful agencies at work during the drift 
epoch. This rock consists of a light grey, flinty limestone, weathering almost 
white, and is far more abundant in corals than in shells. This, it may be observed, 
is the case with the base of the formation wherever met with, while higher up 
the shells predominate. The following are the fossils met with in this place ;— 
Favosites hemispherica.....e0..ee.s+ee.++++++ Vandell and Shumard. 
GUT OUTALD\\oictersrcrversieia aisielecreie cele ... Billings. 
WGA DEE QUDRUEBIS 09G00 caccanDebo DONC abbS D’Orbigny. 
Heliophyllum Canadense.....+...++ee++e-.2-- Billings. 
Syringopora tubiporoides ......... a resets alate Yandell and Shumard. 
Zaphrentis prolificds..siccecestcescaceess +. DININSS, 
—- GUS ANTE \ahelaleiolelohalale aeielelclele = os-ee- Lesueur. 
Eridophyllum Simcoense......0+eeeee++eeee0+ Billings. 
Cystiphyllum grandis ....cc.scccccrsceesses . Billings. 
Strophomena ampla. 
--- depressa. 
Atrypa reticularis oo cscs. sce cdecccccccsccse . Linn. 
Platyostoma ventricosa. 
Platyceras -— (%) 
with fragments of Orthoceras (one species). 
A second and far more extensive exposure occurs in the south-western portion 
of the same township, and extends south-westerly into the township of Middleton. 
It is about the fourth of a mile in width, and two miles long, and consists of a 
dark grey limestone abounding in organic remains, At this place I found no rock 
which appeared to be in its original position, but huge detached portions lay 
scattered in great abundance over the surface of the ground, intermixed with the 
granitic boulders and other detritus of the drift period. Many of these limestone 
boulders are exceedingly large, and are quarried from the ground for various 
building purposes. I examined one which contained thirty cords of stone, and 
was credibly informed that many such had been quarried out where there was no 
appearance of limestone near them. In some places these boulders cover the 
ground so thickly as to render it unfit for cultivation. In the township of 
Middleton, this ridge is cut by Big Creek at Croton Mills. The banks of the 
creek are at this place about ninety feet high, and exceedingly steep, the valley 
presenting the appearance of having been worn by the stream passing through it. 
The bed of the stream is composed of sand, pebbles, and boulders, similar to the 
surrounding country. At a short distance to the west of the creek the limestone 
ceases to appear, although the granitic boulders are as abundant as upon the east 
side. 
