No. 1«L] 193 
into whiting, and, from its pulverulent state, will ere long be large- 
ly used for the improvement of the soil. This marl is abundant in 
recent fresh water shells. 
In some of the water courses which have traversed those rocks 
where limestone abounds, pebbles of this mineral have been car- 
ried to a considerable distance from their source. Thus at Elmi- 
ra, we were told that they were collected at the river, and burnt 
for lime. 
Should those counties ultimately prove deficient in lime, of which 
all future agriculture will make great demand, the well known 
abundance existing in the more northern ones, will afford an am- 
ple and cheap supply, when all contemplated public works shall be 
completed. 
In Erie, Niagara and Seneca, limestone forms a considerable 
portion of the surface rock, being the kinds which Professor Eaton 
has designated by the descriptive names of cornitiferous, geodife- 
rous and calciferous: the former characterized by siliceous mat- 
ter, in the state of hornstone: the geodiferous, by the cavities it 
presents, many of which are partially, or wholly filled up with 
crystallized limstone, or gypsum, either hydrous or anhydrous. 
Some of the cavities contain sulphurets of zinc, or blende, as at 
the Falls of Niagara, and Lockport; but in quantities merely suffi- 
cient for cabinet specimens. The greater number of the cavities 
appear to have been owing to the removal of fossil bodies, particu- 
larly favosites, and cyathophylli. 
At Black Rock, just below the layers of the cornitiferous lime- 
rock of Professor Eaton, there occurs an aggregate of brownish 
red limestone, and dark green shale, analogous to the Compan mar- 
ble of the Pyrenees, only the colours are not so vivid as those of 
the latter. It is not improbable that when a greater extent of 
country is excavated for limestone, this aggregate will be found 
sufficiently bright in colour, to be used as marble. So also, the 
fine partially red coloured encrinal limestone, thrown out in the 
excavations made for the canal at Lockport, there merely forming 
hand specimens, may be discovered in sufficient abundance for like 
ornamental purpose. 
Siliceous Conglomerate^ called also pudding-stone and mill-stone 
grit. This aggregate we meet with in three localities. In Alle- 
[Assem. No, 161.] 25 
