On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 373 
the ridges becoming obliterated, especially in large and mature teeth, towards the 
summits. A large example measures 1°5 inches across the base; the latter extending 
in a semicircle ‘75 of an inch backwards. Height of median cone ‘9 inch, width 
at base ‘4 inch. ‘There are three lateral cones on each side, the outermost largest. 
In other specimens the median cone is considerably thicker and more robust, and 
there are generally two cones only on each side of the principal one. They are more or 
less cylindrical and devoid of cutting edge. 
This species was regarded by Prof. Agassiz as the type of the genus. A magni- 
ficient series exists in the Enniskillen collection from which the beautiful teeth, 
on Plate XLIX., have been selected. 
Formation and locality : Carboniferous Limestone, Armagh. 
Ex coll. Earl of Enniskillen. 
Cladodus marginatus, Agass. 
(Pl. XLIX., figs. 7-9.) 
Cladodus marginatus— Agassiz, L. 1838, “ Poiss. Foss.,” Vol. IIL, p. 198, pl. 22. B, fig. 18-20. 
i leevis—M ‘Coy, F. 1848. “Ann. Nat. Hist,” 2nd ser., Vol. II., p. 133. 
x marginatus—Portlock, J. E. 1844. “Geol. Rept. Londonderry, &ec.,” p. 461. 
es es Giebel, C. G. 1848. “Fauna der Vorwelt,” Vol. I, pt. 3, p. 323. 
53 3 Pictet, F. J. 1854. “Traité de Paleont,” Vol. II., p. 258. 
- leevis— 3 a Pe 5 * Vol. IL, p. 258. 
5 ee M ‘Coy, F. 1855. “ Brit. Paloz. Foss.,” p. 619, pl. 3 K, fig. 5. 
Sp marginatus— . 5 BF ‘ 5. Jd Gl, 
69 . Morris & Roberts, 1862. “Quart. Journ. Geol. Soc.,” Vol. X VIII., p. 100. 
» leevis— i - * = 3 5 W@L NAO, js WOW: 
3 5 Young & Armstrong, 1871. “Trans. Geol. Soc., Glasgow,” Vol. IIT., supt., p. 69. 
Teeth, base, strong, broadly expanded, concave, fitting to the base of the crown. 
Crown, median cone large, thick and strong, generally inclined at an oblique angle 
to the base, obtusely pointed, somewhat compressed, with a raised cutting edge 
along each side, surface finely striated in specimens not greatly worn. Two 
secondary cones on each side, terminal cones divaricating, slightly larger than the 
intermediate ones, short, broadly expanded at the base, obtuse, striated same as the 
median cone. ~ 
Several specimens are much worn by using, the cones being reduced to a short 
stump. In such instances every trace of the surface striation is removed and the 
teeth present a perfectly smooth appearance. The smooth teeth were considered 
by Prof. M‘Coy as separate species, whilst C. mzrginatus, he included in the species 
C. mirabilis, Ag. In both these determinations there can be little doubt that Prot. 
M‘Coy erred. Cladodus marginatus as defined by Prof. Agassiz is quite distinct 
from C. mirabilis of the same author, no amount of wearing would reduce the long, 
cylindrical, distinctly-separated lateral cusps of the latter to the form presented by 
the tormer, ia which the cusps are united together by their bases. In all particulars 
