416 
[Assembly 
this rock as the equivalent of the millstone grit of England, which lies 
beneath all the coal measures. So far as I have been able to trace its 
connexion with rocks above and below, it holds the same place in the 
series. This view of the matter will sufficiently account to those in- 
terested, why I am unwilling to recommend any expenditure in boring 
or other explorations in this rock or beneath it. 
The rules of science are as immutable as the laws of creation, and 
so long as we profess to be guided by science, we must submit to its 
requirements. Because, as in this instance a rock, possessing certain 
lithological characters, is observed, we are not to infer from that alone, 
that the rock may contain the same minerals as another of like charac- 
ter, without taking into consideration the difference of position or as- 
sociations.* 
LIVINGSTON COUNTY. 
The county, of Livingston exhibits principally a continuation of the 
same rocks as are found in Ontario county, and described in the report of 
last year. Beginning on the north these rocks are the Hydraulic lime- 
stone, Onondaga and Seneca Hmestones, the extensive group of fos- 
siliferous shales succeeded by the upper black shale ; the Cashaqua 
shale, the Gardeau and Portage groups. The latter occupies only some 
of the high grounds in the sauthern part of the county. 
The most prominent feature in this county is the great valley of the 
Genesee river, which passes nearly through the centre of the county 
from north to south. This valley in connexion with others, will be de- 
scribed at the end of the report. 
Ht/draulic lifnestone. — The northern part of Caledonia presents a 
view of the hydraulic limestone, which is quarried in several places 
within the town, and also at a little distance north, along the northern 
slope of the terrace. This rock underlies the village of Caledonia, 
and from this place its northern limit is southeasterly to the Genesee 
river. The oblique direction of the outcrop of this and the succeeding 
rocks on either side of the Genesee is owing to the denuding action, 
formerly in operation along this great water course, which removing the 
superincumbent masses, exposes those below farther south and at a low- 
er level. This causes the line of outcrop to bend to the southward on 
* For a continuation of the report on Cattaraugus county see Appendix, Mr. Hors- 
ford's report. 
