380 On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 
small, broadly and strongly implanted, converging to a finely pointed apex. Two 
extreme cones are the largest, they extend away from the centre. 
This specimen appears to be unique. 
Formation and locality : Mountain Limestone, Richmond. 
Hx lveed Collection, Museum, York. 
Cladodus hornei, Davis. 
(Pl. XLIX., fig. 20.) 
Tooth, medium size, 1*1 inch across the base, 1 inchin height. Base, subelliptical, 
thin, anterior face slightly rounded, depressed in centre, extending backwards at 
right angles to the median cone. Median cone long, tapering, with a slight double 
flexure, compressed from back to front ; junction of anterior and posterior surfaces 
from a lateral cutting edge; surface covered with longitudinal ridges about their 
own diameter apart; near the apex it is smooth, apparently the result of wear, 
towards the base the ridges become more numerous and smaller, then disappear. 
Two lateral cones °3 of an inch in length, round, divergent, pointed, striated similarly 
to median cone. Space between the median and lateral cones depressed and smooth. 
This comparatively rare species stands apart from others of the same genus in 
its graceful attenuity and paucity of secondary denticles. It probably approaches 
near to Cladodus striatus, Ag., from the Armagh Limestone, to C. elongatus, Davis, 
from Richmond in Yorkshire, and to C. elegans, N. and W., from the St. Louis 
Limestone (Geol. Survey of Illinois, Vol. IV, p. 354, pl. iv., fig. 9). From the 
latter it is distinguished by the central cone being rounder, less compressed, and 
its attachment to the base less expansive and thinner. The general form of the 
tooth is similar to C. elongatus, but it is readily distinguished from that species by 
the presence in the latter of a large number of lateral cones. ‘The same character 
also separates it from C. striatus as well as its more slender and feebler form. 
I am indebted to Mr. William Horne, an enthusiastic naturalist, for the oppor- 
tunity to describe this species, and as a tribute towards my indebtedness I venture 
to distinguish the species by appending his name. 
Formation and locality : Carbonifercus Limestone, Wensleydale. 
Ea coil. William Horne, Esq. 
Cladodus mucronatus, Davis. 
(EL, SOMO, ties Zilla) 
Teeth, medium size, breadth of base ‘8 of an inch, height of median cone ‘5 of 
an inch, Base thick, median portion, beneath central cone, deeply hollowed, 
abruptly prominent on each side, retreating and terminating in an acute extension 
projecting some distance beyond each extreme lateral denticle. Crown composed 
of a central cone, with five lateral cones, two on one side, three on the other, the 
