Ayres’s Description of a New Genus of Fishes. 63 
ascertain with what genera it can be compared, or even with 
what family it may be arranged. The position of the dorsal 
and anal recalls at once the Esocide, and it would seem 
proper to place Malacosteus with them. But this is a charac- 
ter of only secondary importance. Prof. Miller has shown 
that Belone, which has these two fins situated as in the genus 
Esox, does not even belong to that family. A feature of much 
greater value, and which may be deemed the distinguishing 
characteristic of the Zsocide, is the structure of the upper 
jaw, which is formed entirely by the intermaxillaries ; or, if the 
maxillaries are present, they are destitute of teeth. With 
this, it is evident our genus does not agree, and we must 
look elsewhere for its position and relations. In the Salmon- 
ide we find the upper jaw in general, constructed somewhat 
as in our fish, — formed of both maxillaries and intermaxil- 
laries, the former being furnished with teeth. And with this 
family we may perhaps arrange the genus for the present. It 
exhibits however, many discrepancies, which cause us to doubt 
the correctness of this decision. It has no cceca, no scales, no 
natatory bladder, and no adipose fin. But to no other family 
does it appear to approach so nearly as to the Salmonide, and 
here we must leave it. In this I am influenced more by the 
opinion of Prof. Agassiz than by my own judgment; he 
would place the genus near Scopelus. Wherever placed, 
it is quite evident that it must take a rank indicated by its 
embryonic traits. 
The principal points on which we may particularly insist as 
characteristic of the species and the genus are, the remarka- 
bly small size of the head, and in contrast with this, the 
immense development of the whole facial and branchial 
apparatus, and all that pertains to the mouth and throat ; the 
singular and but partially explained organ on the cheek ; and 
most of all, the embryonic condition of the entire osseous 
System. 
