470 On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 
Labodus planus, Ag. MSS. 
(AL ILAVUIOL, fiers, 41144.) 
Labodus planus—L. Agassiz, . 1859. MSS., Enniskillen Coll. 
FF Morris and Roberts, 1862. “Quar. J. Geol. Soc.,” Vol. XVIIL, p. 101. 
. os Enniskillen, 1867. ‘Cat. Type Speci.,” p. 5. 
5 3 J. J. Bigsby, 1878. ‘Thesaurus Devon.-Carb.,” p. 357. 
Teeth, more generally rounded in outline than L. prototypus, smaller, and the 
lateral expansions of the osseous base less prominent. Length of crown along 
median axis, ‘7 of an inch, breadth ‘6 of an inch. Crown flat or very slightly con- 
vex, ridge bounding the crown laterally slightly raised ; anterior part more or less 
concave from attrition. Coronal surface covered with an exquisite arrangement of 
pittings, presenting the magnified appearance of the facets of a butterfly’s eye ; the 
punctations increase slightly in size towards each side. Anterior margin slightly 
concave, antero-lateral angles obtusely curved ; lateral margins straight, expanding 
a little towards the posterior aspect. Central part of the posterior margin convex, 
with an incurving towards the postero-lateral angles, which are more or less pro- 
minent. Base less constricted than in JL. prototypus, between the anterior and 
posterior margins, wider than crown ‘3 of an inch thick in centre, tapering near 
each side to an acute angle ; transverse section convex, slightly depressed on each 
side the median line; longitudinally the surface is concave. The base extends 
beyond the crown on each side, but not to so large an extent as in L. prototypus, the 
latero-posterior angles are produced to the extent of “1 of an inch, or in some 
instances rather more diagonally in continuation of the angle of the crown. 
This species differs from L. prototypus in its evenly spread crown, round anterior 
angles, and in the lateral prolongations of the base forming a less conspicuous mass 
on each side the crown, as well as in minor details in the basal portion. 
Formation and locality : Carboniferous Limestone, Armagh. 
Ex coll. Kav] of Enniskillen. 
Genus.—Mesogomphus, Agass. MSS. 
Mesogomphus—L. Agassiz, 1859. MSS., Enniskillen Collection. 
Palatal teeth; outline tongue-shaped, posterior diameter equal to length, 
narrowing towards the front. Crown slightly convex, depressed posteriorly with 
a median well-defined semi-circular suture extending inwards from the posterior 
margin ; lateral borders slightly raised ; coronal surface punctate. Anterior margin 
circular, continued, and gradually expanding along the lateral margins ; posterior 
margin convex, postero-lateral angles obtusely rounded. Base thick, transversely 
convex, similar form to crown but extending beyond its posterior margin. 
