Williams.] FAUNAL DISSECTION OF THE DEVONIAN. 73 
(2) Its dominant list of 11 species includes but one of the dominant 
list of the Hamilton formation. 
(3) In the dominant list occur five characteristic species not found 
in the formations below, and two of the five are recognized mutants 
of earlier species. 
'.-,' 
FAUNA OF ITHACA FORMATION AS EXPRESSED IN THE TYPICAL 
LOCALITY AT ITHACA, N. Y. 
In the bulletin referred to a the faunas directly following the Gene- 
see shale in the Ithaca region were fully analyzed into distinct sub- 
faunas, and in later papers the extension of these subfaunas to their 
prevalent common faunas to the east and west was traced. The 
recurrence of Hamilton species was also there distinctly recog- 
nized in a small faunule occurring in the lower part of the Cascadilla 
Creek gorge (station No. 14 N.). The Universit}^ quarry (station 5) 
and the "inclined plane" section on South Hill and outcrops in Fall 
Creek and Cascadilla Creek were examined, and the lists of species 
were reported at that time as containing the typical "Ithaca fauna." 
After the publication (1884) of the bulletin many additional species 
were collected by my students and myself, which were added to the 
collections in Cornell University. Some twelve years later Dr. E. M. 
Kindle (then a student in Cornell Universit}^) made an exhaustive 
study of the Ithaca fauna, and to illustrate this particular fauna put 
together in a valuable memoir all the statistics then in hand. This 
was published in 1896, 6 and for the purpose of the present discussion 
this paper by Dr. Kindle contains by far the best set of statistics in 
sight. 
Ten sections within a few miles of the head of Cayuga Lake, situ- 
ated in the town of Ithaca and in the immediate neighborhood, fur- 
nish the statistics. The number of stations is 54. These range 
through a thickness of 260 feet stratigraphically. I have tabulated 
the species for the purpose of determining their relative values in 
relation to frequency of discovery in the 54 stations examined. 
In all the collections gathered, 84 species were positively identified, 
specifically, by Dr. Kindle. Of the species so recognized, 33 arc 
reported also from the Hamilton of the eastern counties (Prosser), 
and 31 from the underlying Hamilton of the Cayuga Lake section 
(Cleland). 
The stations are not uniformly distributed through the sections, 
and some of the sections contain over ten stations, while others con- 
tain but two or three. They are the chief fossiliferous outcrops of 1 he 
region, presented by ravines, quarries, and occasional outcrops on the 
steep hillsides about Ithaca. They do not, however, present as com- 
et Bull. U. S. Geol. Survey No. 3. 
?>The relation of the fauna of the Ithaca group to the fauna of the Portage and Chemung, by 
Edward M. Kindle: Bull. Am. Pal., No. 6, Dec. 25, L896. Ithaca. 
