No. 275.] 
255 
Bull's quarry, to the left of the road from Sullivan or Canaseraga to 
Clockville, is one of more interest. It is like the old Sullivan, in 
having a thick, superimposed mass upon the plaster, which consequently 
diminishes its value, from the expense of working being too great, 
requiring the whole of materials which covers the plaster to be removed. 
The owners, therefore, of such beds cannot compete with those whose 
gypseus masses are near to the surface of the soil. The following sec- 
tion of the quarry shows an addition of more " vermicular," or porous 
rock, and the presence of hopper shaped cavities and fossil remains. 
7. Third or upper alluvial of Chittenango. 
6. Porous blue limestone rock, (" vermicular,") pores larger 
than usual, and slightly compressed, 3 feet. 
5. Slaty, variegated, gray and blue striped, &c. with a few 
fossils. This mass is the same, with No. 3, of old 
Sullivan, 10 feet. 
4. Thin layers brownish, with a few pores, the whole seeming 
to be decomposed, 3 feet. 
3. Thicker layers, harder, not so dark coloured, with hoppers, 
and at its intersection with No. 4, the lower porous mass, 
pores small, 4 feet. 
2. Light coloured, like No. 3, with hoppers, 2 feet thick. 
1. Like No. 4, dark coloured, with gypsum; the mass to 
which the lower gypsum seems to be confined. 
The fossils are few in number, consisting of fucoides resembling our 
small spear grasses, if charred; also a few bivalve shells, the lingula 
limosa, and two or three undescribed thin shelled bivalves. 
In this quarry we are presented with a phenomenon observable in the 
greater number of plaster quarries of the lower range, and to which in 
part the common opinion entertained, that plaster is still growing, owes 
its origin. This appearance is an arching of the layers which cover the 
plaster, which is more or less regular, as the surface of the plaster 
curved with more or less regularity. It is usually the case that the 
mass or rock of the arch is full of cracks, owing to the force exerted 
by the plaster in its expansion upwards. 
