On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain, 397 
margins °3 inch ; raised portion of crown occupies a position nearer one end than 
the other. Not marked by any different feature to the remainder of the surface 
except that it is a little broader. An acutely raised ridge extends across the cone 
and along the lateral extensions to the extremities. From this a large number of 
minor ridges branch out at right angles. The latter frequently become broken 
into tubercles which extend over the surface mostly near the base. Root not 
exposed. 
This example is placed in the genus Orodus with some doubt; it appears to 
possess many characters in common with other recognized members of the genus, 
but in some respects it diverges considerably. The median cone is less developed 
than in any other species and the tuberculated ridges are peculiar. It appears, 
however, to approach Orodus nearer than Helodus or Lophodus. 
Formation and locality : Mountain Limestone, Bristol. 
Ex coll. Bristol Museum. ; 
Orodus ornatus, Davis. 
(Pl. LI., figs. 9, 9a.) 
Teeth, small, transverse diameter °5 of an inch; antero-posterior diameter °2 of 
an inch ; crown consists of median cone with two or more lateral secondary cones 
on each side. Median cone large, prominent, apex smooth, with a radiating series 
of minute ridges or fuldings of the enamelled surface, gradually absorbed in 
the smooth surface lower down; a carina extends across the cone and is 
continued laterally to the end of the tooth, it is tuberculated along its entire 
length. The anterior and posterior basal margins of the crown are formed by a 
series of folds in the enamel which are continued on the secondary cones. On 
each side of the central cone is a deep depression from which the wall of the 
secondary cone rises at a sharp angle, from its apex it slopes gradually to rise 
again abruptly to form the next cone. An antero-posterior ridge runs across the 
cones, which is also, in most cases, tuberculated similarly to the median carina. 
Root not exposed. 
This species approaches most nearly to O. moniliformis. It differs from it in the 
greater thickness and breadth of the crown, the presence of tuberculate projections 
along the lateral carina and the central cone, and in the form of the secondary 
cones, which are not so round as in O. moniliformis, but present more the form of 
an inverted cone. 
The surface of crown of the tooth now described when magnified presents an 
extremely ornate appearance which has suggested the nomen triviale applied to 
the species. 
Formation and locality : Mountain Limestone, Richmond, Yorkshire. 
Ex coll. Ear] of Enniskillen. 
