484 Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 
contracts in width and divides into two branches; one of these ascends and 
protects the gills, the other is bent over towards the abdominal region. From 
these bones spring the pectoral fins. The latter contain numerous rays, most of 
which are unfortunately hidden from view under the matrix, and their size 
and characters cannot be ascertained in consequence. The pelvic arch, which 
supports the ventral fins, extends from the vertebral column with a graceful 
curve towards the posterior portion of the body (Pl. xvr.); from this there was 
evidently a considerable expansion of the dermal covering of the body; but 
the construction of the fins is not shown with sufficient clearness to render 
accurate description possible. 
A second specimen in the collection at the British Museum exhibits some 
of the features wanting in the one described above. The specimen is one-fifth 
smaller, and is preserved caudally so far as the extremity of the ventral fins. 
The pectoral fins extend from a point 1:5 inches anterior to the line of the 
buccal orifice, a distance along the base of the fin equal to 10:5 inches, which 
is 1 inch posterior of the pelvic arch. There are fifty rays to each fin, and 
of these twenty-eight are placed anterior to the largest median ray opposite 
the scapular arch, and twenty-two are extended along the posterior surface. 
The longest median ray is 3 inches, and from this the external outline of the 
fin becomes gradually attenuated, with a graceful curvature in each direction. 
The rays, averaging 0-1 of an inch at the base, expand slightly with the expansion 
of the fin; they are divided by six or seven articulations, and at the joints 
divide so that a basal ray will, in the succeeding part, support two rays. 
The ventral fins extend backwards from the pelvic arch to a distance of 4 
inches; there are about twenty-four rays, each 0°8 of an inch in length in the 
anterior part, but increasing in length and decreasing in diameter towards the 
posterior extremity of the fin. 
The posterior part of the body, including the tail, is wanting in this 
specimen also. 
Several points of divergence from the species described by MM. Pictet 
and Humbert have been indicated in the foregoing description, and there can 
be no doubt that this specimen must be regarded as a new species which it 
is proposed to distinguish by the name Rhinobatus grandis. 
Formation and Locality—Upper Cretaceous: Hakel, Mount Lebanon. 
Ex coll.—Lewis Collection; Robert Damon, Esq. 
