Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 543 
avons quelque peine a bien apprécier les véritables rapports.” They continue: 
‘“It bears some little resemblance to Beryx and to Pycnosterinx. Its body is, 
as in those two genera, oval and short; its scales are strongly denticulated, 
and its anal fin is supported in front by strong spines. It differs from both 
in the dorsal fin, which occupies the whole length of the back from the occiput 
to the tail; it is supported in front by fine and closely-set rays.” M. Costa 
states that the ventral fins are abdominal, but his plate leaves us in some doubt 
in this respect. 
M. Costa does not indicate the locality from whence this fossil was obtained. 
MM. Pictet and Humbert consider that the specimen had been obtained from 
Sahel Alma, but they had no opportunity of examining it. The example now 
described is from Sahel Alma. 
Formation and Locality.—Soft chalk: Sahel Alma, Mount Lebanon. 
Ex coll—Lewis Collection, British Museum (Natural History Department), 
London. 
Family. STROMATEIDZ, 
Genus. Omosoma. Costa. 
The genus Omosoma was established by Professor O. G. Costa, in 1855, for 
a fossil fish from Mount Lebanon. It was placed in the Scomberoid family, 
approaching Centralophus, from which he considered it was distinguished only 
by characters of minor importance. It is represented as an oval fish, with a 
long dorsal fin, and an anal fin almost as long, pectoral rays small, ventrals 
thoracic, and covered with small smooth scales striated concentrically. 
Omosoma sah-el-almee, Costa. 
(PI, xxy., fies.) 
O. sah-el-alme. Costa, O. G., 1855. ‘‘ Descrizione di alcuni pesci fossili del 
Libano,” p. 10, pl. 1, fig. 1. 
O. sah-el-alme. Picret and Humpert, 1866. ‘Nouvelles recherches sur les 
poissons fossiles du M. Liban.,” p. 45. 
The body is oval; 271 inches in length from the tip of the snout to the 
peduncle of the tail; of this length the head occupies 0°9 of an inch. The tail is 
0:8 of an inch additional. The greatest height, 0-9 of an inch, is midway 
between the head and the tail, and from this point the diameter diminishes 
gradually, and at about the same rate, in each direction. A long dorsal fin 
extends from a point immediately behind the head to the base of the tail, and 
an anal fin from the middle of the ventral surface to the tail. The fish is in 
4K 2 
