BERYCOID FISHES. 



143 



processes of the vertebrae or directly on the centra, and the 

 characters of the post-temporal bone, the teeth, and the barbels. 



The Berycoid fishes (e. g. Beryx splendens, 493, Wall-case 12) 

 are the most ancient and generalised of the Acanthopterygian 

 fishes, and were richly represented in the Upper Cretaceous by 

 several genera (e. g. Hoplopteryx, fig. 65) which are closely related 

 to, if not identical with, the existing genera. They have a short 



Beryx. 



Fig. 65. — Restoration of an extinct form of Beryx, Hoplopteryx lewesiensis. 

 (After A. S. Woodward.) 



body ; the pelvic fins have an exceptionally large number of fin- 

 rays, 6-13 soft rays and one spine. The eyes are large, the cleft 

 of the mouth is oblique, the jaws have small teeth, the bones of 

 the gill-cover are more or less armed w 7 ith spines. In the septum 

 or partition between the two eyeballs is a bone, the orbitosphenoid, 

 which* is present in the more primitive Teleostean fishes such 

 as the Herrings and Salmons, but is wanting in the Perches and 

 Mackerel-like fishes. 



Some of the Berycoid fishes (e. g. Beryx and Holocentrum, 496) 

 have a persistent pneumatic duct to the air-bladder, and this again 

 is evidence of the Berycoids constituting a connecting link between 

 the Physostomous fishes such as Herrings and Salmons and the 

 typical Acanthopterygians such as the Perches. In the recent 

 forms and in some of the extinct forms the tail is deeply cleft, and 



