BUFFALO SOCIETY OF NATURAL SCIENCES 23 
A form very close to Gnathodus mosquensis occurs in the 
Conodont bed and I propose to name this species, the first to 
be discovered in this country, Gnathodus americanus. 
For about one-half of its length the base expands and curls 
upward like a withered leaf. Its upper surface bears a number 
of prominent tubercules. Surmounting the base is a long, thin 
ridge of flat coalesced teeth unequal in heighth. The cavity 
beneath the base is centrally located, of the usual lozenge shape 
and much smaller than that in Gnathodus mosquensis. 
ROEMGINAM EWS PE NINAGECIS El UND Es 
Plate X, figs. 1 to 9. 
1879. Polygnathus pennatus, G. J. Hinde, Quart. Journ. Geol. Soc., 
Vol. XX XV, p. 366, Plate XVII, fig. 8. 
1879. Polygnathus dubius, G. J. Hinde (in part), Quart. Journ. Geol. 
Soc., Vol. XXXV, p. 363, Plate XVI, fig. 17. 
1886. Polygnathus dubius, J. M. Clarke, 6th Annual Report, N. Y. 
State Geologist, Plate A-1, figs. 2, 3, 13. 
1886. Polygnathus pennatus, J. M. Clarke, 6th Annual Report, N. Y. 
State Geologist, Plate A-1, fig. 9. 
The genus Polygnathus was established by Dr. Hinde to receive 
Conodonts of various forms associated together on a single slab 
of shale probably of Portage age, and considered by him to have 
belonged to the same animal. I have given in another place my 
reasons for doubting the propriety of including in one genus all 
of these forms, some of which had already been described under 
various genera. If, for no other reason than convenience in 
classification, in the present state of our knowledge, I believe 
the genus Polygnathus should be restricted, so as to include only 
those tuberculated and rugose tritoral plates discovered for the 
first time with the type specimen and characteristic of it. These 
consist of leaf-shaped plates with a central rib or ridge which 
is produced beyond the tritoral margin into a stem-like flattened 
crest of pectinate teeth. P. pennatus is the smallest and one of 
the commonest of these forms. It ranges in geologic time from 
the base of the Genesee to the Rhinestreet shale in the Portage 
group. Specimens are abundant in the Conodont bed, but many 
of the other forms described together with it as Polygnathus 
dubius are absent. 
Dr. Hinde figured a side view of a specimen of this species 
to accompany his description of P. dubius and in the same article 
figured as P. pennatus an upper view of the same species. Both 
of these specimens, although referred to the Genesee were 
probably collected from the Portage shales. Owing to their 
peculiar shape these fossils have a deceptive appearance when 
variously oriented in the matrix and it is not surprising that 
Dr. Hinde and later, Dr. Clarke, failed to recognize them in their 
