598 Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 
The spinal column consists of fifty-eight to sixty vertebree, of which about 
twenty are caudal. M. Pictet only observed thirty-four vertebra, but that was, 
no doubt, owing to the imperfect preservation of the specimen he described. 
The vertebrae of the anterior part of the body are 0:15 inch in height, and 
less than half that in breadth; they are closely connected, and only slightly 
contracted in the middle; towards the tail the vertebrz are longer, not so high, 
and considerably contracted medially. The ribs are long and slender; the hemal 
and neural spines are stronger; they are numerous, and attached to the apophyses 
of each vertebre. 
The dorsal fin is seen in the specimen figured (PI. xxxm1., fig. 4). It is one inch 
behind the head, and its posterior rays about the same distance from the tail; it 
consisted of thirteen rays in the specimen described by M. Pictet, with which this 
agrees. The anal fin in this specimen exhibits twelve rays: they are shorter than 
those of the dorsal fin, the anterior rays of which are 0:8 inch in length; those of 
the anal fin are about 0°6 inch. The pectoral and ventral fins are similar in 
construction, the latter slightly larger than the former. The pectorals are sup- 
ported by nine or ten rays, and measure 0-6 of an inch in length; they are 
separated from each other on the abdominal surface by a space of 0-6 of an inch 
across. ‘The ventral fins are quite 1:0 inch in length, composed of twelve rays ; 
the outer ones are longest; they are thick, and only divided towards their distal 
extremities. The bases of the two fins are 0:4 inch apart; the space between 
them is occupied by a single large plate, somewhat angular behind, but rounded 
in front ; this is succeeded by others in the posterior direction, which are smaller, 
but still considerably larger than the ordinary scales. The caudal fin is strongly 
supported by rays not only from the hypural bone, but also from several of the 
terminal vertebrae. There are twenty-four rays, and several rudimentary ones 
support both the upper and lower lobes; the rays are jointed and repeatedly 
bifurcate. 
The scales on the sides between the pectoral and ventral fins are 0:2 inch 
in height; the width of the exposed surface is equal to half the height. The 
surface is ornamented by a series of radiating ridges, which terminate on the 
exposed margin in folds, which give it a serrated appearance. The larger scales 
on the abdominal surface, already alluded to, as well as the median plate between 
the ventral fins, are similarly ridged. The scales on the posterior portion of the 
body are slightly smaller than those in front. 
Formation and Locality—Upper Cretaceous: Sahel Alma, Mount Lebanon. 
Ex coll—K. R. Lewis; R. Damon, Esq., Weymouth. 
