136 
ACTING PTEETGUI. 
with opercular apparatus contained somewhat more than three 
times, maximum depth of trunk about four times in the total 
length of the fish to the base of the caudal fin. Vertebrae about 40 
in number, half being caudal. Pectoral fin with about 12 stout 
rays, articulated only quite at the extremity, and the length of the 
foremost equalling half the depth of the trunk at its insertion; 
pelvic fins about half as large as the pectorals, also with relatively 
stout rays, arising much nearer to the anal than to the pectorals 
and opposed to the anterior half of the dorsal; dorsal fin with 15 
rays, slightly deeper than long, the distance between the occiput 
and its origin somewhat less than that between the caudal fin and 
its termination ; anal fin arising a little in advance of the middle 
point between the pelvic and caudal fins, the total number of the rays 
being 13, and the hinder 5 or 6 of these widely spaced along the 
ventral border almost to the base of the caudal. Ventral ridge-scales 
25 in number, gradually diminishing in size behind the pelvic fins. 
Form.^' Log. Upper Cretaceous: Mt. Lebanon, Syria. Cretaceous; 
Istria ; Isle of Lesina, Dalmatia. 
P. 4747. Pine specimen displaying all the principal characters of 
the genus and species, shown of the natural size in 
PI. VI. fig. 1 ; Hakel, Mt. Lebanon. The fish is exhibited 
in direct side-view, with the cheek and U 2 :)per jaw crushed 
a little forwards. The form of the relativelv small 
%/ 
cranium is distinct, and the delicate parasphenoid is 
gently bent upwards at the anterior end of the otic region. 
Eemains of the large pterygo-quadrate arcade occur 
beneath the cranium, the articular end of the quadrate 
(^M.) for the support of the mandible being directly under 
the anterior margin of the orbit. The premaxillae 
are shown, one being imperfect, the other onU in 
impression ; and these are proved to be longer than deep, 
though small compared with the maxillae. One maxilla 
(apparently the left viewed from within) is especially well 
preserved (ai.r.), exhibiting its convex oral border and a 
remarkably large anterior inwardly-directed process; but 
?io teeth are distinctly seen, merely some fine transverse 
striations on the oral margin in its hinder half. Above 
the maxilla are remains of the two characteristic supra- 
maxillary bones. The mandible (cZ.) is remarkably short 
and deep, partly obscured by fragments of cheek-plates ; 
scarcely more than the anterior third of its upjier margin 
can have entered the cleft of the mouth. Postero- 
