230 
SELA.CHII. 
Genus ORODUS, Agassiz. 
[Poiss. Foss. vol. iii. 1838, p. 96.] 
An indefinable Carboniferous genus known only by teeth, which 
are not generically distinguishable from those of the Mesozoic 
Hybodus. The teeth, however, are not associated with other 
remains characteristic of the latter genus, and may thus be regarded 
as pertaining to a distinct fish. They are laterally elongated, 
having the coronal contour raised mesially, and the surface orna¬ 
mented by more or less prominent transverse wrinkles, rising from 
each long margin, or from a median longitudinal crest. The root is 
often much deeper than the crown. 
It is probable that the dorsal fin-spines originally named Ctena- 
canthus pertain to this genus \ 
Orodus cinctus, Agassiz. 
1838. Orodus cinctus , L. Agassiz, Poiss. Foss. vol. iii. p. 96, pi. xi. 
figs. 1-4. 
1878. Orodus cinctus , L. G. de Koninck, Faune Calc. Carbf. Belg. pt. i. 
p. 31, pi. iv. fig. 2. 
1883. Orodus cinctus, J. W. Davis, Trans. Roy. Dublin Soc. [2] vol. i. 
p. 392, pi. 1. figs. 8, 9. 
Type. Detached teeth ; Bristol Museum. 
The type species, of medium size. Median coronal prominence 
large, more or less rounded : longitudinal median ridge rounded, 
nearly even; transverse ridges and furrows broad and large. 
It is uncertain at present to what extent the rounded character 
of the teeth of 0. cinctus is due to post-mortem abrasion. Except 
in size, the teeth exhibit a very close approximation to those of 
O. ramosus, as already remarked by L. G. de Koninck and J. W. 
Davis. It seems advisable, however, to retain the species provision¬ 
ally distinct. 
Form. Sf Loo. Bone-bed of Lower Limestone Shales: Bristol. 
Lower Carboniferous Limestone (Bed I e ) : Tournai, Belgium 2 . 
P. 2713. Abraded tooth, figured by J. W. Davis, loc. cit. pi. 1. 
ho-. 9. Enniskillen Coll. 
P. 1472. A broken similar, but less abraded tooth. Ecyerton Coll. 
1 See especially J. S. Newberry, Rep. Geol. Surv. Ohio, vol. ii. pt. ii. p. 54. 
2 A very doubtful tooth from the Lower Carboniferous of Russia is also 
recorded under the name of 0. cinctus by H. Trautsehold, Norv. Mem- Soc 
Imp. Nat. Moscou, vol. xiv. (1879), p. 52, pi. vii. fig. 2. 
