398 On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 
Orodus moniliformis, Davis. 
GAL IGiL, ies, UO, Wi, 12) 
Teeth, medium or small, transverse diameter one inch, central cone largest, 
more or less circular, separated by a deep sulcus from the secondary cones, of which 
there are four to six on each side, diminishing in size towards each lateral extremity 
of the tooth. Surface in small specimens smooth ; in larger ones, the apex of each 
cone is minutely striated ; lower part corrugated trom the base of the crown upwards 
but disappearing before reaching the apex. Between each corrugation there are 
a number of small transverse plications, near and parallel to the base, which are 
continuous from the central round the lateral cones. Root short, not so wide as 
the crown, coarse in structure, containing numerous lacune. 
This species is characterized by its somewhat flattened crown and short root, and 
more especially by the semi-detached appearance of the cones forming the crown. 
It bears a superficial likeness to Orodus mammillaris, N. and W. (‘Paleeont. of 
Illinois,” Vol. IL., p. 66, pl. iv., figs. 10, 10a) ; the cones in the latter have a greater 
vertical altitude, the ridges are more prominent and frequently beaded, of which 
there is no trace in the Orodus now described. The root of O. mammillaris is also 
shorter than in this one. 
From Orodus ornatus, Dav., of the Richmond limestone, it is readily distinguished 
by the absence of small tubercles along the lateral carina and central cone, which to 
some extent are characteristic of that species. 
Formation and locality: Mountain Limestone, Armagh. 
Ex coll, Earl of Enniskillen. 
Orodus reedi, Davis. 
(Pl. LL, figs. 13, 18a.) 
Teeth, small, probably °7 to ‘8 of an inch in transverse diameter; height of 
crown ‘2 of an inch, antero-posterior diameter about equal to the height of the crown, 
median cone prominent, anteriorly and posteriorly dilated forming a bold ridge 
from which minor ones branch right and left, reaching to the base, laterally 
compressed : a carina extends from the median cone, on each side, at right angles 
to the median one named ; bold ridges, separated by deeply channelled grooves, 
branch out from the central carina and descend to the base of the crown. At least 
one secondary cone occurs on each side the median one and its ornamentation is 
similar to the median one. Surface uniformly and coarsely punctate. Root, 
concavo-convex, structure open and porous. 
The peculiar arrangement of the ornamentation of this tooth (as shown on Pik 
fig. 13a) separates it from any other species hitherto described. It is very elegant 
and though the extremities of the tooth are broken off, the part existing is well 
preserved. 
