On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 479 
Genus.—Mylax, Agass. MSS. 
Mylax—L. Agassiz, 1859. MSS. Enniskillen Collection. 
Palatal teeth, broader than long. Crown, longitudinally convex ; transversely 
flat, enamelled, rugose or punctate. Anterior margin, concave ; posterior 
margin, convex ; lateral ones, convex. Palates succeeded each other on the same 
plane, the convex posterior margin fitting tc the concave anterior one of the tooth 
preceding it ; terminal tooth anteriorly convex. Base strong, with lateral processes 
extending diagonally beyond the crown. 
Mylax batoides, Agass. (MSS.) 
(Pl. LVIII., figs. 25, 26.) 
Mylax batoides—L. Agassiz, 1859. MSS. Enniskillen Collection. 
- rs Morris and Roberts, 1862. “Quart. Journ. Geol. Soc.,” Vol. XVIII, p. 101. 
5 Enniskillen, 1869. “Catalogue Type Spec.,” p. 6. 
.s J. J. Bigsby, 1878. <‘‘Thes. Devonico-Carb.,” p. 359. 
Teeth ; breadth -9 of an inch including basal projections beyond the crown; 
breadth of single teeth 15, and of two together “3 of an inch. Crown divided into 
two teeth, anterior one °55 of an inch in breadth, the posterior one “7 of an inch 
in breadth: transversely, flat; longitudinally convex along the whole breadth. 
Surface enamelled, rugose, with intermediate pittings. Anterior margin concave 
with obtusely rounded antero-lateral angles, Lateral margins convex ; posterior 
margin convex in centre, hollowed towards each side and produced to form acute 
postero-lateral angles. A suture separating the two palates extends transversely 
across the specimen parallel with its posterior border, at a distance of ‘15 of an 
inch. Base moderately thick, partially hidden by matrix. Anteriorly and pos- 
teriorly it does not appear to extend beyond the crown, laterally, forms aliform 
processes which extend diagonally -2 of an inch, at an angle of 45° from the latero- 
posterior margin of the crown. Ina second specimen, smaller than the one already 
mentioned, the posterior palate is very much less than the anterior one, longitu- 
dinally it occupies ‘1 of an inch, whilst the one in front of it is ‘2 of aninch. The 
anterior margin in this instance is convex, and the anterior portion of the coronal 
surface is considerably worn by attrition. It is probable that the convex 
anterior tooth in this specimen is the terminal one, and that a similar palate origi- 
nally occupied a position in front of the concave anterior margin of the specimen 
first described. 
The genus Mylax approaches more nearly to those of Dimyleus and Pinacodus 
than to any others. In Pinacodus, however, the anterior palate is much smaller 
than the posterior, the reverse of the case with Mylax. The latter is extremely 
broad in comparison to its length, and the base extends in large processes beyond 
the lateral margin ; in Pinacodus the crown and base are co-extensive, and the tooth 
TRANS. ROY DUB, SOC., N.S., VOL. I. 4E 
