16 THE GENESEE CONODONTS 
Dr. Hinde was disposed to doubt the propriety of placing these 
teeth in Prioniodus, but Pander’s definition is broad enough to 
include them. Like Prioniodus recedens, there are progressive 
forms varying from simple to compound teeth, and rights and 
lefts can be distinguished. 
PRIONIODUS RADIATUS, HINDE 
Plate 1V, figs. 10-12: Plate V; mgs. 1-5, 8: Rlate Vin fig. 5: Plate Vili 
figss ly 2a45 O98): Plate: Xel Ve whioe il: 
1879. Polygnathus radiatus, G. J. Hinde, Quar. Jour. Geol. Soc., Vol. 
XXXV, pv. 364. Plate XVI, fig. 20. 
1879. Polygnathus dubius (in part), G. J. Hinde, Quar. Jour. Geol. 
Soc? Violh XOOL Vip) 3025 Plate XV hash Onandas) 
1886. Polygnathus dubius (in part), J. M. Clarke, Report of State 
Geologist for 1885, Albany, N. Y., Plate A-1, fig 6. 
This species 1s no less variable than the preceding form. The 
main tooth is always broad, slightly convex and inclined to the 
base; sometimes produced below it to form the walls of the 
lozenge-shaped cavity. The base is narrow, arched and bears on 
either side of the main cusp a row of denticles varying in size 
and often so closely crowded together that they seem to have 
interfered with each others growth. The main cusp is also 
frequently constricted below and the whole appearance would 
suggest that the normal expansion of the base was prevented by 
the encroaching bases of adjoining plates. The flattened base 
often expands at either end. 
As in other species these jaws or plates occur in pairs. They 
resemble in form the teeth from the Russian Devonian described 
as Ctenognathus verneuilli by Pander, and supposed by him to 
differ from Prioniodus in their cellular microscopic structure. 
The Genesee teeth, however, as shown rather obscurely by the 
photomicrograph of the thin section on Plate XIV, fig. 1, agree 
rather with Prioniodus in their internal laminations. 
PRIONIODUS CEAVATUS: EIEINDIE 
Penne. WAL Samer. Sh, (0: 
1879. Prioniodus clavatus, G. J. Hinde, Quar. Jour. Geol. Soc., Voll. 
XXXV, p. 360, Plate XV, fig. 16. 
This species is uncommon in the Conodont bed and it is 
difficult to find specimens which are not partly concealed by the 
matrix; while in the weathered and washed material the long, 
slender teeth are nearly always broken. The teeth are often more 
closely opposed than those shown in Dr. Hinde’s figure. As 
many as seven or eight teeth are sometimes found on one side 
of the main cusp which is not so greatly differentiated from the 
others as in most species of the genus. 
