Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 487 
flowing sygmoidal curvature. The scapular bones connecting ‘the vertebre to 
the divaricating bones supporting the fins extend on each side only 0°5 of an 
inch, and thence the scapular bones extend forwards and encircle the head, 
and backwards encircling the thoracic cavity. From these extend sixty rays, 
repeatedly jointed, and occasionally dividing at the joints into two smaller rays. 
The ventral fins are small: they are supported by a pelvic arch, which is 
attached to the vertebree at a distance 2°2 inches behind the pectoral one; from 
this arch the fin extends backwards 1:2 inch; it is supported by 10-12 rays 
08 of an inch in length. 
At the extremity of that portion of the caudal region preserved there 
remains the base of the first dorsal fin. It was cartilaginous, without osseous 
support ; there is not a sufficient portion preserved to indicate its size or form. 
The example now described approaches nearer in its peculiar characteristics 
to Rhinobatus latus, but it differs in several material and important respects. 
In R. latus the thoracic cavity is large and wide, the head also is widely 
expanded, and the pectoral fins are obtusely triangular in outline. In this 
species the body cavity and head are comparatively small in proportion to the 
size of the fish, whilst the pectoral fins are greatly expanded and have a triangular 
outline with quite an acutely pointed apex. Beyond the ventral fins the caudal 
region of the body is very small and attenuated as compared with that of R. latus. 
In consideration of the wide extent of the fins of this species it is proposed 
to distinguish it by the nomen triviale expansus, Rhinobatus expansus. 
Formation and Locality.—Upper Cretaceous: Hakel, Mount Lebanon. 
Ex coll—tLewis Collection, British Museum. 
Rhinobatus tenuirostris, Davis. 
(PI-x1x, fic. 1) 
A remarkable specimen, collected by Mr. Lewis, and now in the national 
collection at the British Museum, is characterized by the possession of an 
extremely long and pointed snout. The anterior portion of the body is well 
preserved, and exhibits the relative proportions accurately. The caudal extremity 
is absent. The portion preserved is 18 inches in length: of this length the 
snout and head takes 11 inches, the remaining 7 inches being posterior to the 
pectoral arch. The greatest width across the pectoral fins is about 8 inches, 
the base of the tail 2 inches. The width of the head at the termination 
of the pectoral fin and 8 inches behind the tip of the snout is 3:5 inches, 
and from this point the margins of the snout gradually converges and terminates 
in a prolonged and attenuated extremity. The pectoral fins have a greater 
resemblance to the prolonged and rounded form of Rhinobatus grandis than 
3X 2 
