Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 481 
of the thoracic vertebre afford evidence of the attachment of short rudimentary 
osseous ribs or spinous processes. 
The pectoral fins are moderately large but not very well preserved; they 
are 15 inches in length. The basal portion of both the pectoral and ventral 
fins was supported by a series of elongated ossicles 0°2 of an inch in length, 
from which the cartilaginous portion of the fin extended. The anterior insertion 
of the pectoral fin is 4°7 inches behind the snout; the ventral fins 2°5 inches 
behind the pectorals. 
The unpaired fins are represented only by the anal and caudal. From 
the circumstance of the ventral surface of the fish being exposed the dorsal 
fins are hidden from view. The caudal fin is 4:2 inches in length; the vertebre 
extend to the extremity of the upper lobe, which is 0°6 of an inch in depth, 
gradually tapering backwards. The lower part of the tail is comparatively 
small, extending only 1 inch along its base and 0:2 beyond the line of the 
superior lobe. The anal fin is placed 1 inch behind the termination of the 
ventrals ; its base extends 1:3 inches in length, apparently without any ossified 
supports. It is small, depending 0°38 of an inch from the ventral surface of 
the body ; a space of 1:2 inches separates it from the caudal fin. 
Formation and Locality.—Upper Cretaceous: Sahel Alma, Mount Lebanon. 
Ex coll.—Lewis Collection, Mr. Damon, Weymouth. 
The head and portion of the body of a Selachian, from the Lewis Collection, 
now in the British Museum, possesses peculiarities with regard to its dentition 
which closely resemble those described above, and, though from a larger fish, 
appear to be the same species. The fragment is 7°5 inches in length, and of 
this 5-0 inches is included in the head. The snout is not complete, a portion 
of the extremity being absent. The part preserved extends 2-0 inches beyond 
the mouth, and gradually diminishes in height. The mouth is large, the upper 
jaw is 3:0 inches in length; it is replete with conical sharply-pointed teeth, 
slightly curved inwards on the anterior portion of the jaw, with smaller base 
than those behind. The latter are 0:16 inches across the base, with a large 
central cone 0:13 in height, and one lateral cone on each side. The teeth of 
the lower jaw are longer than those of the upper and are narrower at the 
base; the larger on the anterior surface of the jaw are 0:2 inches in length. 
The posterior portion of the head and the part of the body shown are badly 
preserved, and do not afford any details for description. This fish is readily: 
distinguished from Notidanus lewisii by the great length of the snout, the 
sharply-pointed and long teeth, and the smaller size of its fins. 
