Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 541 
The dorsal fin comprises twenty-nine rays, the anterior ones spinous. The 
base of the fin extends from the base of the tail 1:2 inches. The distal extremities 
of the rays are absent, so that their length cannot be given; for the same reason 
it is not easy to distinguish how many of the rays are spinous, because the 
proximal portion of many of the articulated rays are also solid. The anal fin 
is similarly imperfect with the dorsal. The three anterior rays are spinous, 
and these are followed by twenty articulated rays. The caudal fin is absent. 
The pectoral fin cannot be distinguished; there appears to be, however, a 
slight impression on the lateral surface indicating its position. The ventral 
fins are both exposed, closely impinging on the median abdominal line; nine 
or ten rays can be distinguished, the anterior ones strong and robust. The 
scales are small; patches are preserved, but their form is not distinguishable. 
Formation and Locality—Upper Cretaceous : Hakel. 
Ex coll.—British Museum, Natural History Department. 
Genus. Imogaster, Costa. 
I have had no opportunity of seeing the type of this genus. MM. Pictet and 
Humbert remark that this genus is placed with some doubt with the family 
Chromides. It possesses some relationship with Beryx and Pycnosterinx. Its 
body is, as in those genera, oval and short; its scales are strongly denticulated ; 
and its anal fin is sustained in front by a strong spine. It differs from both 
in the dorsal fin extending the whole length of the back from the occiput to 
the tail, supported in front by fine and serrated rays. M. Costa states that 
the ventral fins are abdominal. Though I have not seen the original type of 
this genus, described by Professor Costa, there can be little doubt that the 
specimen here described and represented is the same species. 
Imogaster auratus, Costa. 
(Pl sxyit., figs.) 
I. auratus. Costa, O. G., 1855. ‘‘ Descrizione di alcuni pesci fossili del Libano,” 
psy pl. 1.) fig: 2: 
I. auratus. Picrer and Humpert, 1866. ‘Nouv. rech. sur les poiss. fossiles du 
Mont. Liban.,” p. 44. 
Length of the body, exclusive of the tail, 2°7 inches; height 2-2 inches, 
immediately behind the head, is maintained to the base of the anal fin. The 
tail, widely expanded in this specimen, will add about 0:5 inch to the length. 
TRANS. ROY, DUB. SOC., N.S. VOL. II. 4h 
