30B 
I Assembly 
Manchester to that village it approaches the surface, and could easily be 
obtained in any required quantity. Thence it extends west to the 
quarries in Mendon, though the surface of the intervening space is 
mostly covered with deep alluvium. 
At Maffit^s quarry, in Phelps, the drab limestone is succeeded by 
several feet thickness of bluish gray limestone, which divides into thin 
laminae by parallel seams; when struck with a hammer, it yields a 
metallic sound, like some of the trap rocks. On the surfaces of the 
laminse are found Cytherina and a species of Orthis, which are the only 
fossils I have seen in connection with the drab limestone. This rock, 
when exposed to the weather, presents numerous linear or needle form 
cavities, frequently almost covering the surface of the stone; these 
result from the decomposition and removal of thin crystals of strontian 
which have pervaded the entire mass. Specimens are frequently ob- 
tained where the crystals are preserved, and others where they are only 
partially removed. 
Tke Oriskany sandstone^ is well characterized in the Third Geologi- 
cal District, and described by Mr. Vanuxem; it appears but at one 
point in this county, and not at all in Seneca, being either entirely 
wanting or deeply covered with superficial materials. This rock could 
be easily identified did it exist, but I have yet seen it only in Flint 
creek, at Vienna. Here it is a coarse porous sandstone, destitute of 
fossils, so far as observed, with the exception of a single specimen of 
Icthyodorulite; the large Orthis and Delthyris, which characterizes this 
rock in the Third District being entirely wanting. Its purely silicious 
character and porous texture are well adapted to withstand the effects 
of rapid heating and cooling; and at the locality mentioned it is much 
quarried for free stone, and used in the Ontario furnace, and in the 
glass furnace at Clyde. It contains numerous small geodes lined with 
chalcedony; also rounded masses of a dark rock are imbedded in its 
surface. These, on examination, prove to be very compact aggrega- 
tions of fine sand, coloured with carbonaceous matter, and may have 
resulted, as well as the chalcedony, from the long continued action of 
Thermal waters. 
At the place where this rock is quarried, it is four feet thick, divided 
into two or three layers, one of which is about two feet. It rests im- 
mediately on a slaty, argillaceous limestone, four feet thick, which 
succeeds the water lime proper. The thin layer of conglomerate men- 
tioned in the report of last year as separating the drab limestones at 
