480 Davis— On the Fossil Fishes of the Chalk of Mount Lebanon. 
Genus. Rhinognathus.* Davis. 
Body fusiform; snout much prolonged and spatulate. Head occupies one- 
fourth the entire length. Buccal orifice large. Teeth of anterior portion of 
each jaw long and pointed; posterior teeth, broader and shorter central cusp, 
with a smaller one on each side. Vertebree numerous; pectoral and ventral 
fins well developed. Anal fin nearer to the ventrals than to the caudal 
Rhinognathus lewisii, Davis. 
(Pl. x1v., figs. 4, 4a.) 
Length, 16 inches; largest diameter between the pectoral fins 1:5 inches, 
tapering backwards to the tail and forwards to the snout, which is prolonged 
considerably beyond the mouth and terminates more or less pointedly. The 
ventral aspect of the fish is uppermost, exposing the pectorals, ventrals, anal 
and caudal fins; the mouth, with teeth, is exhibited, and the branchial apparatus 
can be distinguished. The surface of the body was enveloped in a cuticular 
covering, with minute tubercular dermal ossifications. 
The head occupies more than one-fourth the entire length of the fish, and 
is 4:5 inches from the tip of the snout to the posterior portion of the branchial 
apparatus. The anterior portion of the mouth is situated 2:2 inches behind the 
extremity of the snout, and it extends backwards with a somewhat acute 
curvature a distance of l inch. The teeth vary in form: those occupying the 
anterior surface of the jaws are long, round, acutely conical and sharply pointed, 
slightly expanded towards the base, without lateral denticles. Posteriorly the 
teeth gradually become less acutely pointed, shorter, and more widely expanded 
at the base. Those furthest back have an obtusely triangular apex and broad 
base, more or less striated. The majority of the teeth are without lateral 
cusps, but the smallest teeth are possessed of a minute lateral cusp on each 
side. The mandibles are well developed, and are represented in the figure 
extending to the branchial apparatus. The latter extends from the vertebra 
on either side, consisting of five branchiostegal rays, apparently with serrated 
margins for the attachment of the gills. 
The vertebral column is not so distinctly preserved as might be desired. 
The thoracic vertebre are 0:15 of an inch in length and about the same in 
diameter. They gradually decrease in size towards the caudal fin. There are 
about 130 vertebre in all, and of these 67 are included in the tail. Some 
* piv, a snout; yvabos, a jaw. 
