410 TRANS. OF THE ACAD. OF SCIENCE. 
Niagara Group—This member occupies a narrow 
cme A a a of a mile in width, extending fom from oa 
ne about five miles above the mou th, nearly west 
ra 5 Faniioa? Ml on Mill Creek. It is entirely wanting = 
northern half of the county. The beds are well d 
the St. — and Farmington road, about a mile west of the 
_ present here a thickness of not less than 150 
oe ; 
at an angle of from 80° to 90°, and the beds have been consi- 
derably altered by volcanic agency, being converted into an 
extremely beautiful variegated marble of remarkably fine 
texture, and quite brittle. The tools passes through various 
shades of flesh-color, ami green, pink, purple, and choco- 
late, and in some masses the different colors are — 
and corre rennd Slended, 
Lower Sivvurian. 
