444 On the Fossil Fishes of the Carboniferous Limestone Series cf Great Britain. 
Teeth, ‘Terminal posterior tooth sub-cylindrical, obliquely attenuated semi- 
elliptically. at the posterior end, abruptly truncated at an angle of 80° in front, 
strongly convoluted, with three very strongly-marked, very prominent, nearly 
equidistant ridges ; the lateral ones formed by the thickened reflexed margins of 
the anterior and posterior edges; the middle one thicker than the others, and 
slightly more prominent, bounded on each side by a very broad, deep concavity ;. 
the concavities are crossed by strong, subequal, slightly irregular longitudinal 
wrinkles, separated by deep suici, which only indent the oblique transverse ridges 
of the convoluted outer portion; the whole surface strongly granulo-punctate.”— 
(I£Coy.) ; 
‘The length of the specimen figured is °75 of an inch across the lateral diameter 
and ‘4 of an inch antero-posteriorly. It differs from P. jonesti, Ag. in several 
particulars ; the postero-lateral angle is less prominent, whilst the radiating ridges. 
on the surface are much more so, especially the two lateral ones. The posterior 
half of the tooth in P. jonesii is large compared with the remainder, whilst in 
P. obliquus it is smaller and hollowed by the deep concavity between the postero- 
lateral and median ridges. The inside margin is much more inrolled in P. obliquus 
than in P. jonesii, Ag. It has been hinted that some relationship may be found 
to exist between the Sirenoid Ganoids and the Cochliodonts ; should such be the 
case, it will probably be found that the teeth of this species will approach as near 
as any to connect the two forms together. 
Formation and locality : Mountain Limestone, Armagh. 
Ex coll. Karl of Enniskillen. 
Peecilodus corrugatus, Davis. 
(GEE JIU, sivey, 2155)) 
Teeth, probably anterior, sub-triangular, -45 of an inch long, and °3 of an inch 
in breadth. Lateral margin slightly curved, gradually approaching and meeting 
posteriorly, forming a slightly inrolled point. Anterior margin circular, depressed. 
The surface of the crown is slightly convoluted antero-posteriorly, and in the 
opposite direction convex. Parallel with the anterior margin four wide, obtusely- 
prominent ridges occupy the central portion with deep intermediate sulci—the 
ridges terminate before reaching the lateral margins. Attached to the tooth isa 
portion of a second, probably the larger posterior tooth. The surface is uniformly 
punctate. 
This example, from the Upper Limestone beds of Wensleydale, is similar in form 
to the anterior tooth P. jones, Ag. It differs in being rather flatter, and in the 
surface arrangement. ‘he crown of P. jonesii is raised medially in the form of a 
ridge sloping to each side, with about eight transverse folds. In the present in- 
stance four prominent transverse ridges occupy the surface with a special median one. 
Formation and locality : Upper Limestone, Wensleydale. 
Ex. coll. W. Horne, Esq., Leyburn. 
