Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 527 
Genus. Cheirothrix. Picter and Humperr. 
Cheirothrix. Pricrer and Humpert, 1866. ‘‘ Nouy. Rech. sur les Poissons fossiles 
du Mont Liban.,” p. 51. 
This genus was founded by Messrs. Pictet and Humbert, and its general 
characters stated in terms, of which the following is a translation :—‘ Body 
narrow and long; skeleton slender; head attenuated anteriorly; jaws small, 
straight, armed with small conical teeth; dorsal fin commences immediately 
behind the head, composed of long filiform rays; pectoral fins also composed of 
very long and small articulated rays; ventral fins inserted in the vicinity of the 
pectorals, and composed in part of long rays and in part of short ones.” To this 
may be added that the anal fin is of medium size and extends to the base of the 
caudal ; the latter is large and deeply lobate. 
The genus was founded by the learned authors on a single specimen of fossil 
fish from the soft chalk of Sahel Alma, which is imperfect and somewhat 
disturbed from its natural position. The authors state that they had great 
difficulty in recognizing its several parts, and they place it provisionally and 
with diffidence in the family of the Gobioids. The discovery of other specimens 
has rendered possible the elucidation of several of the characters of the genus, 
more especially with regard to the pectoral and ventral fins. The difficulty 
experienced by Prof. Pictet in deciding which were the pectoral and ventral fins 
immediately disappears on referring to the examples figured on Plate xxvr., in 
which it is clearly shown that the pectoral fin was attached to the lateral surface 
of the body, whilst the ventral is situated on the lower median line, beneath the 
pectoral. Both are large fins, and capable of great expansion. The ventrals are 
the larger, and furnished with the strongest rays. 
In addition to the species described by MM. Pictet and Humbert, a second one, 
from the same locality, will be added. 
Cheirothriz hbanicus, Pictrer and HumBeErr. 
(PI. xxv1., figs. 3, 4.) 
C. libanicus. Picrer and Humpert, 1866. ‘‘ Nouv. rech. sur les poissons fossiles 
du Mont Liban.,” p. 52, pl. u., fig. 1. 
The description of this species, though founded on a single specimen, renders 
a further description for the most part unnecessary. The anterior part of the 
body was well preserved, the posterior was absent. Other and more perfect 
specimens have been discovered, and have proved that the species was not an 
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