98 H. 8. Williams—Fauna of the Chemung Group. 
Productus dissimilis Hall (not Koninck). 
Rhynchonella a Dugnue. Martin (a variety approaching young of R, 
acuminata Mart 
Orthis impressa, var. ecu Hall. 
Fragments of Crinoid rate in abundance. 
Strophodonta arcuata 
Strophodonta arcuata, var. ae the same (=“Str. gquadrata Calvin.”) 
Atrypa aspera, var. _ cident alis 1, 
acpi occiden 
Fen Sp. 
S ae pe es H 
Spirifer Hungesfordi H. (a single imperfect shell, but corres- 
ponding with this species in all characters preserved). 
Strophodonta canace H. and W. 
Strophodonta ? re ersa H. 
Strophodonta, n. s. (presenting Hak characters of S. reversa, but 
not resupinate, as that speci 
Chonetes, sp. 
Rhynchonella § ? eontracta, H., 67, p. 4 
Fish Spines (? Ctenoc anthus, near a vA formosus type), and a 
species of Zaphrenti. 
Besides these, Professor Clarke has identified : 
“Streptorhynchus Chemungensis.” 
mS hal disjunctus,” 
“ Extremity of mandible of Rhynchodus.” 
“ Ambocelia umbonata,” and a few other forms which the author 
has not seen. 
A comparison of this fauna with that of Lime Creek, near 
Rockford, Iowa, reveals a remarkable likeness, and especially 
ainong the species characteristic of the latter fauna. Although 
strikingly Carboniferous in aspect, several of its species are like 
those of Western ‘‘ Hamilton” deposits, in which group it 1s 
retained by C. A. White, Hepork on Geol. Iowa, i, 1870. But 
the appearance of a large majority of the species in rocks, in 
New htk State, known to be in the lowest part of the Che- 
mung group, calls for a reconsideration of the whole question 
as to the equivalency of the beds concerned. 
In 1858 (Iowa Geol. Rept., i, Pt. II), Professor Hall described 
a number of species from Lime Creek and the neighborhood 
of Rockford, Iowa, which he then referred to the Hamilton 
oup. Afterwards, upon a more careful study of the rocks 
anc species, Professors Hall and Whitfield described more spe- 
cies from the same beds, and referred the beds to the ‘“Che- 
mung group.” (23d Report on Cabinet, New York State, 
1878. This paper was prepared for the report of 1869, but was 
not published till 1873.) 
