Williams.] FAUNAL DISSECTION OF THE DEVONIAN. 75 
Before further discussing this list it may be well to present the list 
of dominant species of the eastern region where the underlying 
Hamilton formation contains the standard Tropidoleptus carinatus 
fauna, above which the sedimentation was continuous. It may be 
inferred that the latter fauna was not driven out from this eastern 
region, but lived on continuously, suffering only genetic evolution, 
uncomplicated b} T the effects of shifting its habitation. The distribu- 
tional values of the species will be furnished by the statistics of the 
eastern faunules. 
Analysis of the statistics gathered by Professor Prosser in the east- 
ern counties of New York a shows a larger number of species in the 
formation than is reported by Kindle. This increase is probably 
due to the wider area examined, presenting, undoubtedly, local dif- 
ferences in original environmental conditions. The localities from 
which the faunas of the Ithaca formation are reported bj 7 Prosser are 
67 in number, and are distributed from Smyrna, Chenango County, 
through Chenango, Otsego, Delaware, and Schoharie counties. 
The faunules contain 100 species. Of these, 78, or over three-quar- 
ters, occur also in the standard Tropidoleptus fauna. All the 12 
species of the dominant list of the Tropidoleptus fauna occur also in 
the faunules of the Ithaca formation. These 12 species, arranged in 
the order of their distributional dominance in the Ithaca formation, 
are shown in Table XIV, the first column representing collections 
from 07 localities, the second, collections from 14 localities. 
Table XIV. — Productella speciosa fauna: Twelve dominant species of the Tropi- 
doleptus fauna found also in the Ithaca formation of the eastern counties of 
New York. 
[The starred species occur also in the Portage formation.] 
1. Spirifer pennatus 
*2. Tropidoleptus carinatus 
3. Nucula bellistriata 
*4. Palaeoneilo constricta . _ 
*5. Nuculites oblongatus . . 
*6. Phacops rana . - 
*7. Nucula corbuliformis . 
8. Ambocoelia umbonata . . 
9. Athyris spiriferoides _ . - 
10. Nuculites triqueter 
*11. Spirifer granulosus 
12. Chonetes coronatus 
31 
13 
31 
13 
i 
4 
7 
4 
6 
5 
6. 
5 
6 
4 
o 
3 
2 
2 
2 
2 
2 
2 
2 
1 
« Classification and distribution of the Hamilton and Chemung series of central and eastern 
New York, Part 1, by C S. Prosser: Fifteenth Ann. Rept. State Geologist New York, L895, pp 
87-225. 
Idem, Part 2: Seventeenth Ann. Rept. State Geologist New York, 1W0, pp. 67-327. 
