26 
ICHIHrOIOMI. 
Cladodus vachsmuthi, St. John & Worthen, tom. cit. p. 263, 
pi. iii. figs. 1-7. — Kinderhook Limestone ; Iowa. 
Cladodus zygopus, Newberry & W orthen,Jo^. dt. vol. ii. (1866), 
p. 25, pi. i. figs. 9, 10. — Chester Limestone ; Illinois. 
A portion of the skeleton, with the teeth, of a species allied to 
C. mirabilis, from the Carboniferous Limestone of East Kilbride, 
Lanarkshire, has been briefly noticed by R. H. Traquair (Geol. 
Mag. 1888, p. 82), and will be described in the Trans. Geol. Soe. 
Glasgow. 
A fragmentary fossil, apparently the base of a cephalic spine of 
Hybodus, from the Rhaetic Bone-hod of Aust near Bristol, has been 
described under the name of Cladodus curtus, J. W. Davis, Quart. 
Joum. Geol. Soc. vol. xxxvii. (1881), p. 424, pi. xxii. fig. 9. 
Genus DICENTRODUS, Traquair. 
[Geol. Mag. dec. 3, vol. v. 1888, p. 86.] 
Teeth of the same type as those of Cladodus, but having the 
crown unsymmetrical, consisting of one largo cone, with a smaller 
cone on one side only — the latter rarely absent. 
Dicentrodus bicuspidatus, Traquair. 
1881. Cladodus^bicuspidatus, R. H. Traquair, Geol. Mag. [2] vol. viii. 
p. 35. 
1888. Dicentrodus Ucuspidatus, R. II. Traquair, loc. cit. [3] vol. v. 
p. 86. 
Type. Detached teeth ; Edinburgh Museum. 
Usual length of tooth from | to j inch. Base narrow, slightly 
reniform, gently convex behind, and slightly notched in front at the 
base of the principal cone. Principal cone varying much in slender- 
ness, smooth, acutely pointed, sharply carinated on both sides from 
its origin, more or less flexed backwards, and sometimes also 
inclined to one side. 
Form. ^ Loc. Middle Carboniferous Limestone (Blackband Iron- 
stone) : Borough Lee, near Edinburgh. 
P. 2295. Large tooth, one cone being broken away and shown in 
impression (PL VI, fig. 7). 
Presented by Mrs. Burton, 1882. 
P, 4496. Seven small teeth, two shown in PI. VI. figs. 8, 9. 
Presented by Dr. B,. H. Traquair, 1884. 
