Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 483 
The vertebral column is well preserved; the vertebree consisted, when living, 
of an ossified centrum, the anterior and posterior surfaces of which are round 
and prominent, the median portion contracted and rugose; anteriorly to the 
scapular or pectoral arch the branchiz are attached; behind the arch are a 
series of twenty to twenty-two ribs on each side, their bases connected with 
the spinal column by ligaments. So far as can be distinguished there are no 
spinous processes from the vertebra. In the figure of Rhinobatus maronita (Joc. 
cit.) the ribs are seen extending beyond the pelvic arch, and the total number is 
less than those which are in front of it in the present specimen. The number 
of vertebree preserved or indicated in this specimen is probably seventy: of 
these there are twenty-four between the scapular and pelvic arches. In front 
of the scapular arch twelve or fourteen vertebre give support to the skull, 
and the remainder, not so well defined as those already named, extend beyond 
the pelvic girdle. The ribs average 2°5 inches in length, and extend from the 
spinal column with a considerable curvature backwards. 
The head, as already stated, is 8-5 inches in length and the same in breadth. 
A number of teeth indicate the position of the mouth (Pl. xvi.): it was 3 inches 
wide, and extended in an almost straight line transversely across the head 
at a distance of 4:5 inches from the termination of the snout. The teeth 
are small, not more than 0°5 of an inch across, somewhat flattened antero- 
posteriorly, and rounded laterally, with an obtuse edge; they are apparently 
much better adapted for crushing invertebrate food than for seizing and masti- 
cating other fishes. The teeth are coated with a white dentine or enamel, 
smooth and highly polished. The snout is circular in outline; on the line of 
the mouth it is 5 inches across, from thence it is gradually rounded off to 
the anterior extremity, as represented in the drawing (Pl. xv1., fig. 1). The 
cranial cartilage forming the anterior rostral process was supported by a large 
more or less osseous plate); this commences immediately in front of the upper 
jaw, where it is 1°5 inches wide, and extends to a point 0°6 of an inch behind 
the extremity of the rostral process. The under surface of the plate, which 
is the one exposed, is convex laterally, and slightly so antero-posteriorly. It 
consisted of a chondroid substance closely packed with rounded ossifications. 
A second plate extended in the opposite direction from the neighbourhood of 
the lower jaw to the scapular arch; it is nearly 3 inches in length, and anteriorly 
1-4 inches in breadth, diminishing to 1:2 inches posteriorly. To this plate the 
branchiostegal rays appear to have been attached; the method, however, is not 
well defined. The rays were large and strong, separated from each other by 
intervals of 0°5 of an inch: five on each side can be distinguished, and dependent 
from them there were numerous secondary supports for the gills. 
The scapular arch is formed by large and flattened bones attached to the 
vertebral column. At a distance of 2°3 inches from the vertebre the bone 
