BUFFALO SOCIETY OF NATURAL SCIENCES 5 
successive ages. It was partly for this purpose that I undertook 
a re-study of the forms occurring in the Conodont bed of the 
Genundewah Limestone, a rock well known to be of Genesee age. 
Before proceeding further it is advisable to discuss briefly 
the nature of the rock in which the specimens described in this 
paper have been found. The Genundewah limestone emerges 
from the bed of Eighteen Mile Creek in Erie County at the rail- 
road bridge rather more than a mile from the mouth of the 
stream. It here constitutes the base of the Genesee group and 
consists of two closely opposed strata, sometimes separated by a 
thin layer of shale, sometimes merging into each other and 
having a maximum thickness of more than two feet.1 The upper 
member was formerly known as the Styliola limestone, and is a 
hard, dense rock consisting almost entirely of the minute shells 
of Styliola fissurella closely meshed together, although Conodonts 
and plant and fish remains are not uncommon. Fig. 1 is a photo- 
micrograph of the weathered surface of the rock showing the 
closely packed shells. 
- This interesting limestone was first fully described by Dr. John 
M. Clarke® and in line with his deep water theory of the origin 
of the succeeding black shales, he has more than once referred 
to this rock as a typical Pteropod ooze.* 
In modern seas Pteropod ooze ranges from 400 to 1,700 
fathoms,* a greater depth than most geologists would be disposed 
to assign to the deposits of the epi-continental ancient seas* and 
in this connection it should not be forgotten that Dr. Paul Pen- 
‘Not four to six inches as stated by Houghton, Bulletin Buffalo - 
Society of Natural Sciences, Vol. XI, p. 34. j 
7On the Higher Devonian Faunas of Ontario County, N. Y., U. S. 
Geological Survey Bulletin 16, p. 14. 
“It is, however, more homogenous than the modern Pteropod ooze 
owing to the absence of Heteropods, etc. 
*Sir John Murray. The Depth of the Ocean, p. 169. 
“I have busied myself much with recent deep sea sediments, have 
studied those of the Challenger Expedition and in my geological studies 
have considered again and again whether anywhere a fossil rock pos- 
sesses abyssal characteristics, and can state that nowhere have I met 
with a rock either from Palaeozoic or Mesozoic deposits that by its 
structure and nature of deposition corresponds to the present sedi- 
ments of the deep sea.’—Dr. Johannes Walther, American Journal of 
Science, 4th Series, Vol. XXXI, p. 60. 
