Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 525 
mouth is small, apparently less than one-tenth of an inch aperture. A number of 
minute teeth, round at the base, with a pointed apex, extend around the orifice, 
and others, rounded and flat, may be distinguished on the posterior surface of 
the jaws. From the maxilla upwards, the anterior cranial surface is depressed ; 
it, however, resumes its convex form, and the bones coalesce, forming a prominent 
and elevated mass, triangular at its base, tapering rapidly, and terminating at its 
superior extremity in a sharp point, like a spine. The orbit is comparatively 
small, and is situated immediately below the triangular part of the bone forming 
the upper portion of the skull. 
The spinal column extends with a somewhat sygmoidal curvature, first 
upwards from the head, thence ventrally, and again it ascends with a decided 
inclination towards the upper lobe of the tail. The number of vertebre is 
indefinite, but there are probably between twenty and twenty-four; they were 
osseous and deeply bi-concave, very high in proportion to their length. Neural 
spines are connected with each vertebra; they are strong, and of considerable 
length. Connected with these are interneural spines, usually double the number 
of the neural spines, but occasionally three branch from one of them. The 
interneural spines expand towards the surface, and afford a strong basal support 
to the rays of the dorsal fin. The heemal and interhzmal spines supporting the 
anal fin are arranged symmetrically with the neural. The ribs are small, slender, 
and not very numerous, decreasing in length as they approach the occiput. 
The dorsal fin extends from the highest point above the head to the base of 
the tail; it is supported by thirty-five rays, expanded at the base for attachment 
to the interspinous bones, and divided and subdivided towards the opposite 
extremity. The anterior rays are the longest, the length rapidly decreasing 
towards the tail; the longest ray is at least 0-7 inch in length; it is supported in 
front by two or three shorter imbricating spinous rays. The anal fin has 
twenty-two rays; the anterior ones are thick and strong, not so long as those 
which immediately follow, but sharply poimted. The fin is not perfectly 
preserved, and the length of the rays cannot be ascertained. They diminish 
posteriorly. The caudal fin is deeply cleft, forming two lobes, each 0°25 inch in 
length; each lobe contains twelve to fourteen rays. 
The pectoral fins are small, with eight short rays, supported by the pectoral 
arch. The latter extends parallel with and immediately behind the opercular 
apparatus. The fin is situated midway between the axis of the vertebral column 
and the abdominal surface. From the pectoral arch a strong bony process 
descends to support the ventral fins. The latter, in this specimen, are not 
preserved. 
The body of the fish was covered with thin scales, which are preserved in 
small patches, but not sufficiently well to afford any information as to their form 
or characters. 
TRANS. ROY. DUB. SOC., N.S. VOL. II. 4C 
