Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 561 
0-1 of an inch across, the middle of the vertebra is contracted. The body being 
closely covered with scales, the characters of its skeleton are not well defined. 
The neural and hemal spines are especially well developed near the tail, and 
indicate that this fin was strong and calculated for rapid progression, 
The dorsal fin is 0°8 of an inch behind the occipital region of the head; 
its base extends 1-6 inch along the dorsal margin of the body, and it terminates 
1-4 inch from the caudal. The fin is supported by about thirty rays; the 
anterior rays are little short of an inch in length; they are strong, and for half 
an inch undivided; beyond this they are articulated and dichotomize; the 
posterior rays are shorter. The anal fin is 0-4 of an inch from the base of the 
caudal, and its base extends 0°5 of an inch; it comprises eight strong rays; the 
longest anterior one is 0°6 of an inch in length, and similar in construction to 
the rays of the dorsal. The caudal fin is large and powerful, deeply forked, and 
composed of thirty rays, fifteen in each lobe; the external rays of each lobe 
are supported by a number of imbricating rudimentary rays, The base of the 
fin-rays is connected with the last caudal vertebra by strong radiating bony 
plates. The rays are articulated and divide repeatedly into eight or more 
filamentous branches. Of the paired fins the pectorals are absent. The ventrals 
are 1:3 inch in advance of the anal; the rays are eight in number, and 0°35 of 
an inch in length. 
The scales are arranged with a sygmoidal curvature of the transverse series, 
seventeen scales extending from the dorsal to the ventral surface. A line of 
scales from head to tail, parallel with the lateral line, which cannot be distin- 
guished, numbers forty-six to forty-eight. The scales are more or less rounded 
on the exposed margin; they are 0-1 of an inch in length, and about half that im 
width. The surface is raised into six to eight ridges, which terminate on the 
margin in a serrated edge. The dorsal scales behind the dorsal fin are com- 
pressed, so as to form a serrated ridge; the abdominal scales are likewise 
elongated and angular, and. present an appearance similar to that characteristic 
of the genus Clupea. 
Formation and Locality.—Upper Cretaceous: Sahel Alma, Mount Lebanon. 
Ex coll_—Lewis Collection ; R. Damon, Esq., Weymouth. 
Osmeroides latus, Davis. 
(Pl: xxx. fig. 1.) 
The specimen of which the following is a description is in two parts, exhi- 
biting the left side of the anterior part of the body and the right side of the 
posterior ; placed on the opposite halves of the matrix. The length of the fish is 
8-0 inches from the snout to the base of the tail; of this the head occupies 
2-0 inches. The length of the tail, in addition to the above, is 2‘0 inches. The 
