Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 515 
Hoplopteryx oblongus, Davis. 
(Pl xxys fig. 1) 
The specimen represented on the plate indicated above is well preserved for 
the most part, though it is unfortunate that, whilst the outline of the head is 
clearly shown, the bones themselves have been removed. The body of the fish, 
from the snout to the base of the tail, is 6-0 inches; including the tail, it is 
75 inches in length. The greatest height is in front of the dorsal fin, 2-7 inches ; 
from thence, with well-rounded outline, the height diminishes to the peduncle of 
the tail, which is 0-7 inch in height. 
The head is large, 2:5 inches in height posteriorly, diminishing towards the 
snout. The orbit is situated medially. The gape wide, and the jaws equal in 
length, and strong. Unfortunately the bones of the anterior portion of the head 
are absent, and the dentition cannot be seen, except two or three scattered teeth, 
which are small, conical, and pointed. The opercular bones were rounded on 
their posterior surface, and considerably higher than broad; they appear to have 
covered a considerable area on the lower posterior portion of the head. The 
upper cranial surface is covered with scales, smaller than those on the body, but 
imbricated in the same way. The branchiostegal rays are only represented by 
fragments. 
The spinal column consists of thirty-two vertebre; of these fourteen are 
caudal. Large and robust spinous processes extend from the hzemal and neural 
surfaces of the vertebrae, and interspinous bones support the dorsal and anal fins, 
The ribs were probably small; they are hidden by the covering of scales and 
matrix. The vertebrz are strong, 0°2 inches in height and 0:15 in length, 
becoming slightly shorter towards the occiput. 
The dorsal fin commences immediately behind the head, and probably extends 
2'5 inches along the dorsal surface. The length of its base cannot be exactly 
determined, the posterior portion of the fin not being preserved, but the distal 
extremities of the fin-rays are shown. ‘The anterior part of the fin consists of six 
or seven spinous rays, thick and strong, tapering to a point; they are a little over 
1:0 inch in length. In front of these are other rays, shorter, similar in form, and 
curved slightly backwards. Beyond the spinous rays there was a number of soft 
jointed rays, of which the only part preserved is the distal extremities. The anal 
fin, like the dorsal, is strongly supported by interspinous bones. Its anterior ray 
is 1:5 inch from the base of the caudal, and its posterior rays extend to within a 
quarter of an inch of it. A series of spinous rays precede the soft rays of the fin 
behind. The latter are numerous, divided, and jointed, decreasing in size back- 
wards. The caudal fin is deeply bifurcated. Each lobe consists of nine principal 
rays, about 1°5 inch in length; a number of shorter rays fill up the intermediate 
