512 Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 
The bones of the head are not sufficiently well preserved to render their 
identification very certain. The opercular bones are large, rounded on their 
posterior margin and smooth. The jaws are displaced; no teeth are visible. 
The spinal column consists of twenty-eight vertebrae, of which thirteen are 
caudal. The vertebree are longer than high towards the caudal fin, but near 
the head the height equals or slightly exceeds the length. The ribs are long 
and slender, the posterior ones with branching epipleural spines. The neural 
and hzmal spines are stronger than the ribs, and extend with a slightly sygmoidal 
curvature backwards. A series of strong interneural spines support the rays 
of the dorsal fin, and smaller interhzemal spines those of the anal. The posterior 
termination of the vertebral column gives rise to a large triangular hypural 
bone, from which extends the rays of the caudal fin. 
The vertical fins are represented only by the dorsal and caudal. The anal 
fin, placed 1 inch behind the ventral, and 0-2 inch before the caudal, is only 
represented by the bases of a few of the rays. The dorsal fin is abnormally 
developed. The anterior rays extend to a length of 1:9 inch. They are strong 
at the base, and taper to a point. The posterior rays are shorter. There are 
nine rays in the fin; and besides these there are a number of fin rays extending 
some distance towards the tail. They are short, not exceeding 0:2 inch in 
length anteriorly, and diminishing to 0:1 posteriorly. The caudal fin is bilobate 
and deeply cleft. The upper lobe is longer than the lower. Each consists of 
about twelve rays, dichotomizing and forming a filamentous extremity. They are 
articulated. 
The pectoral and ventral fins are not well preserved. The position of each 
can be traced. The pectoral fin is situated immediately behind the operculum ; 
the ventral, 0°6 inch behind the pectorals. The ventral fins are opposite to the 
dorsal. 
The scales are small, smooth on the surface, and minutely serrated on the 
posterior margin. 
The general characters of this specimen appear to associate it with Pseudo- 
beryx. The form of the body is similar to that of P. syriacus, P. and H., and 
the number of vertebrz and their division into caudal and abdominal is the same. 
The arrangement of the fins agrees in each as to their relative position; though 
the ventral and anal fins are not preserved in the specimen now described, their 
position is clearly indicated. Whilst the generic relationship is thus clearly 
defined, the great length of the rays of the dorsal fin readily distinguish it 
specifically, and the specific name (longispina) has been given to it as indicating 
this peculiarity. 
Formation and Locality—Upper Cretaceous: Hakel, Mount Lebanon. 
Ex coll—Prot. Lewis, in the possession of R. Damon, Esq., Weymouth. 
