522 Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 
evidently existing between the dentition of this family and the genera Thyrsites 
and Lepidopus. Professor Agassiz remarks: ‘It is probable that the fossil 
genus differs from the living Scomberoids in that the large teeth are not limited 
to the anterior border of the jaw, but extend along its entire length. Small 
teeth exist in the spaces between the larger teeth; the latter vary consider- 
ably in dimensions and are very irregularly disposed. The extremity of the 
jaws are furnished with several small teeth between the larger ones. The 
external surface of the large teeth is flatter than the internal surface, which is 
more or less circular; the edges are sharp. 
MM. Pictet and Humbert include the genus Isodus, Heckel, in that of 
Eurypholis (‘‘ Poissons foss. du M. Liban.,” 1866, p. 105), under the impression 
that the fragment of a jaw named by Professor Heckel was the jaw of Eury- 
pholis. This has been proved by more recently acquired and more perfect 
specimens to have been an error. It also appears probable that the genus 
Isodus is the same as Enchodus. The description of the former by Heckel is 
identical with that of the latter, so far as the types served; that of Isodus 
consisted of the anterior part of a lower jaw, with only three teeth preserved. 
Both were published in the same year, but that of Agassiz had been for some 
time previously identified by the name he gave it; for that reason the priority 
should rest with Agassiz, and the name Enchodus be retained. 
As already stated, Professor Agassiz identified the relationship of this genus 
with Lepidopus and Thyrsites from the Miocene of Licata in Sicily, and with 
Anenchelum, from the Eocene of Glaris, and placed them amongst the Scom- 
beride. Dr. Giinther (‘‘ Study of Fishes,” p. 433) has placed them in the family 
Trichiuridee along with the recent genera Trichiurus, Lepidopus, Thyrsites, 
and others, characterized by a long compressed body and wide mouth, armed 
with strong teeth in the jaws. 
Enchodus recurvus, Davis. 
@lixxvs diz. 6:) 
Lower jaw 3°3 inches in length, 0°5 in depth, at a distance of one and a-half 
inches from the anterior extremity. The anterior portion of the jaw narrows 
towards its termination, on which are several small teeth. From the alveolar 
surface rise eight teeth, separated by varying distances. The teeth are irregular 
in size and shape. The anterior one is the largest; only the base is preserved ; 
it is 0°13 inch in diameter, double that of any other. The second laniary tooth is 
comparatively small, next four larger, and the two posterior ones again smaller. 
The internal surface of the jaw is exposed. The teeth from the base upwards 
bend outwards; they recurve, almost with a sigmoidal curvature, towards the 
point. The teeth are not so compressed as those of Enchodus halocyon, Agass., 
