AND DEVONIAN CONODONTS. 367 
beyond the plate ; the convex surface covered with small tubercles. 
Length 3 line. A variety of this form (fig. 13) appears to have no 
keel whatever, but a simple tuberculated surface. 
Loc. Bear Creek, Ontario: from the Genesee Shale. Also from 
North Evans, New York: from the “Conodont-bed” of the Hamilton 
group. 
Potyenaruvs punctatus, Hinde. (Pl. XVII. fig. 14.) 
Plate unsymmetrical, flat and thin; a delicate keel which does 
not reach to the tip, but is produced beyond the lower portion of the 
plate and has two or three nodes on it; the surface of the plate is 
covered with very minute tubercles. Length 3 line. 
Loc. North Evans, New York: Genesee Shale. 
Potyenatuvs Lincuirormis, Hinde. (Pl. XVII. fig. 15.) 
Plate elongate, one extremity produced into a tongue-like pro- 
jection, bending downwards; the sides of the plate curving upwards, 
forming a central trough, from the bottom of which tie keel rises, 
this extends some distance beyond the sides of the plate and has an 
expanded crenulated crest. The anterior tongue-like projection has 
several strongly-marked transverse ridges; the lateral surfaces have 
a few scattered tubercles. Length about 1 line. This peculiar 
form is very abundant. 
Loc. North Evans, New York: from the Conodont-bed of the 
Hamilton group. Also in erratic boulders in Genesee Shale on north 
shore of Lake Erie, Ontario. 
Potyenatuus patmatus, Hinde. (Pl. XVII. figs. 16 & 17.) 
Plates elongated, with an unsymmetrical, partially lobed outline, 
depressed in the central portion, a longitudinal keel, and sometimes 
a delicate transverse one, extending from one side only to the central 
depression ; surface smooth and polished and with traces of con- 
centric lines; the reverse side of this form also appears to be smooth. 
Length yarying from 3 line to 1} line, and width between 3 line 
and 2 line. 
In the smooth surface and very irregular outline this differs from 
all the preceding varieties of these plates. ‘This form is very 
abundant and widely distributed. 
Loc. Kettle Point, Bear Creek, Ontario ; North Evans, New York ; 
near Louisville, Kentucky: Genesee Shale. 
Potyenaruus ? simpLEx, Hinde. (Pl. XVII. fig. 18.) 
Jaw ? resembling a tenter-hook in shape and nearly oval in section ; 
the proximal extremity is smooth and rounded like that of an arti- 
cular surface ; a prominent ridge extends in a median line from this 
end to near the tip of the hook; the surface of the jaw above this 
ridge is smooth and glistening, whilst below it very fine parallel 
Q.J.G.8. No. 139. 2D 
