492 Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 
The head is divided into two almost equal parts, the anterior containing 
the organs for mastication, sight, &c.; unfortunately they are not in such a 
state of preservation as to enable a description to be given of them. The 
posterior half is occupied by the branchiostegal apparatus; a large median bone 
extends along the centre from which the branchiostegal rays are suspended, 
apparently five in number. 
The vertebral column is composed of 17 vertebrae between the pectoral and 
ventral arches: they are short, averaging 0°5 inch in length and 0-2 of an inch 
in height. The caudal extremity of the vertebral column is altogether wanting. 
The pectoral fins are remarkably extended. The scapular arch is very strong. 
The median bones connected with the vertebral column are 0°35 of an inch in 
diameter, and extend from the centre 0-9 of an inch from their distal termination ; 
large curved bones divaricate, enclosing the circular cavities of the head and 
thorax; these in turn afford attachment to the rays supporting the great pectoral 
fins, numbering on each side fifty-four. The rays from the two fins meet 
anteriorly and extend in a straight line from the anterior extremity of the head 
a distance of at least 2 inches. From this point they radiate laterally, resolving 
the form of the anterior portion of the body to a slightly elongated oval. 
The posterior rays are 2°5 inches in length and stronger than those anteriorly ; 
each ray is about 0°1 of an inch in diameter, depressed, jointed, and distally 
bifurcated. Their surface is covered by rows of dermal ossicles of a similar 
character to those on the surface of the body. The ventral arch is 1°5 inches 
behind the pectoral. The median transverse osseous support of the fin at a 
distance 0:2 of an inch from the centre of the vertebral column branches in 
three parts: the first and strongest backwards to support the ventral fin; the 
second tends diagonally backwards about 0°8 of an inch, and may have been the 
basal portion of a clasper; the third part extends anteriorly one inch in length 
in the pectoral cavity, from a diameter of 0-1 of an inch it tapers evenly to 
a fine point. The ventral fins are not well preserved, but sufticient remains 
to show that the fin was comparatively small, with eight to ten rays. 
This species differs from Cyclobatis oligodactylus, Egerton (Proc. Geol. Soc. 
Lond., 1844, vol. 1v, p. 442, pl. v.), in the larger number of the pectoral rays, and 
in their broadly expanded, depressed character. The number of vertebrz in this 
species is greater than in C. oligodactylus, and they are characterized by having 
a much greater diameter and consequent strength. 
Formation and Locality.—Upper Cretaceous: Hakel, Mount Lebanon. 
£z coll.—Tristram Collection, British Museum. 
