On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 381 
outermost of which are largest; central cone widely implanted, rapidly tapering 
and terminating in an acutely pointed apex. Surface covered with longitudinal 
ridges, bold and prominent, about twenty in number near the base, diminishing to 
five or six near the apex. Secondary denticles, terminal ones largest, divergent, 
broad at the base, conical, slightly curved, pointed, striated as median cone ; inter- 
mediate denticles small. 
This species, with its sharp, regularly conical cusps and deeply suleated base, is 
readily distinguished from Cladodus mirabilis, Ag., which is the only species which 
it nearly approaches. 
Formation and locality : Carboniferous Limestone, Wensleydale. 
Ex. coll. William Horne, Esq. 
Genus.—Carcharopsis, Agass. MSS. 
Carcharopsis—Agassiz, L., 1833. “Rech. sur les Poiss. Foss.,” Vol. III, p. 313. 
Teeth, length equal to twice greatest breadth ; form triangular, broad at the 
base converging to a pointed apex, straight or slightly bent towards one side ; 
transverse section elliptical or ovoid ; antero-posterior diameter equal to half the 
lateral one ; lateral margins deeply crenulated. Base somewhat constricted and 
less than the diameter of the basal portion of the crown, divided more or less into 
two branches with a deep intervening sulcus. 
Prof. Agassiz in a foot note to the synoptical table of Squalides (‘‘Poiss. Foss.,” 
Vol. III., p. 313), makes the following brief reference to the teeth of Carcharopsis 
prototypus :—<I have designated under this name a very extraordinary type of 
tooth, obtained from the Carboniferous Limestone of England and Ireland, of which 
I shall give a description in the supplement of this work. In their general form, 
the teeth of this genus strikingly resemble those of the genus Carcharodon ; they 
are equally compressed, triangular and denticulated alone their edges, but the 
surface presents large folds towards the base of the crown. The genus appears to 
approach that of Petalodus of Owen, of which it may be necessary to form a separate 
family. The only example I have seen of Carcharopsis prototypus forms part of 
the collection of the Earl of Enniskillen.” 
From the above references to the resemblance of the new genus to those of Carcha- 
rodon and Petalodus there can be little doubt that the tooth which is here described 
as the type of the genus from the collection of the Earl of Enniskillen, and which 
has been so labelled during many years past, is the example which Prof. Agassiz 
intended to indicate. This being the case it necessarily follows that the determina- 
tions of some American paleontologists will require considerable revisions and 
modification. . | 
Prof. M‘Coy (‘British Palseoz. Rocks and Fossils,” p. 642, pl. 3 G, fig. 2, and 
pl.3 K, fig. 11) describes two species of teeth which he considers form a genus possess- 
ing distinctive characters from others previously discovered. They are named 
