550 Davis—On' the Fossil Fishes of the Chalk of Mount Lebanon. 
lines. The surface of each scale is also covered with striz, branching on each 
side from the central ridge and extending backwards; the under surface of the 
scale, in addition to being striated, is also punctured, and has a corresponding 
central ridge, which may serve, in some way not very clearly defined, to interlock 
one scale with another. 
Immediately in front of the ventral fin there is a large ovoid plate 0°7 inch 
in length and 0-4 in greatest diameter; the median surface is raised along the 
longitudinal axis: its surface is covered with pustulate corrugations; the under 
surface is also pustulate. The plate appears to have occupied a median position 
on the abdominal surface; other large plates, similarly ornamented, are scattered 
about the anterior portion of the specimen, but their exact position or relationship 
is difficult to determine. One plate, probably the operculum, is an inch in 
diameter; it is produced, like the scales, posteriorly so as to form a point. 
Formation and Locality —Hard chalk: Hakel, Mount Lebanon. 
Ex coll.—Tristram Collection, Natural History Department, British Museum, 
London. 
Family. SCOMBRESOCIDZ2. 
Genus. Exoccetoides. Davis. 
Body small and attenuated ; skeleton slender; head large and broad between 
the orbits; intermaxillary present. Pectoral fins very large, attached laterally 
to a strong process of the pectoral arch; ventral fins abdominal, much smaller 
than the pectoral; dorsal fin small, situated posteriorly ; caudal soft and fila- 
mentous; anal not seen. 
Two species of the genus Cheirothrix have been previously described, both 
from the soft chalk of Sahel Alma. The specimens constituting this genus are 
from Hakel. They differ in most important respects from Cheirothrix, and 
these differences will, perhaps, be more easily understood by referring to the 
plate. The pectoral fins in Cheirothrix are lateral, but smaller than the ventrals. 
In this genus they are similarly attached to the lateral surface of the body, 
but they are very much larger than the ventrals. The latter are comparatively 
small, and are attached to the abdominal surface considerably behind the pectorals ;, 
in this respect it differs from Cheirothrix, as it does also in the position, character, 
and size of the dorsal fin. In proportion as it differs from Cheirothrix, it 
approaches Exoccetus, and there can be little doubt that there is in this genus 
a prototype of the flying fishes of the present day. In the latter the large 
pectoral fins are placed on the side of the body; the ventral fins are small and 
abdominal; the dorsal situated posteriorly, and near the tail. It will be seen 
from the description following that the fossil approaches very closely to the 
