Chemung and Catshill.— Stevenson. 27 
A remarkable feature of the Chemung is the non-fossiliferous 
area of southeastern New York and the adjacent portion of 
Pennsylvania, northward from Huntingdon county, of Penn- 
sylvania, the upper limit of the Chemung fauna descends; 
in Columbia county the upper half of the Montrose red shales 
yields no fossils, while in Carbon county, no fossils were found 
until practically below the place of the A//egrippus conglomerate ; 
and, even in these lowest beds, fossils are rare and usually not 
“well preserved. No molluscan fossils were found by Prof. White 
in the Delaware river section until considerably below the place of 
the Allegrippus, whence downward ‘‘the whole series is sparingly 
fossiliferous.”* Hven remains of fishes are wanting aside from 
‘the occasional appearance of what appear to be fish-bone frag- 
ments in calcareous breccias.” A similar condition is observed 
as one comes eastward along the border of Pennsylvania and 
New York; Chemung fossils reach the top of the group at the 
western border and in McKean county; but in Tioga county the 
barren space at the top of the column is 165 feet; in Bradford, 
800 feet, in Wayne, 1,170 and in Pike, 2,650 feet, in each case 
inclusive of the Catskill, which, however, does not exceed 300 
feet even in Pike county. 
The area in which the lifeless portion of the column reaches 
much below the horizon of the Lackawavcen conglomerate, em- 
bracing parts of Carbon, Monroe, Pike and Wayne counties of 
Pennsylvania, and of Sullivan, Delaware, and Greene counties of 
New York, contains rather more than 4,000 square miles, while 
the whole area under consideration is more than 30,000 square 
miles. ‘To explain the absence of life is not easy; it cannot be 
due merely to an agent which caused the redness or greenness of 
the beds, for, in Huntingdon and Fulton counties of Pennsyl- 
vania, the Montrose shales have many fossiliferous beds though 
having also many green and red beds. Besides, the Delaware 
section shows a great thickness of beds of other colors, which 
are equally without animal remains. It cannot be due to chemi- 
cal conditions existing in a closed sea, for the successive subdi- 
visions of both Catskill and Chemung can be traced directly into 
the lifeless area equally from the open sea at the west and along 
the Appalachian shore from the south, thus showing that no closed 
sea existed in that area. Kven plant remains are rare, being 
*Geology of Susquehanna River region. pp. 103 and 105. 
