XXIII ACANTHOPTERYGII 655 
Fam. 1. Berycidae.—One or several of the suborbitals 
emitting an internal lamina supporting the eye; entopterygoid 
present. Anterior vertebrae without transverse processes ; all or 
most of the ribs inserted on the transverse processes where these 
are developed. Two nostrils on each side. Gill-membranes free 
from isthmus; 4 to 10 branchiostegal rays; gills 4, a slit 
behind the fourth; pseudobranchiae. Lower pharyngeal bones 
separate. Ventral fins with 1 spine and 6 to 13 soft rays. 
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Fic. 400 .—Beryx splendens, 4 nat. size. (After Goode and Bean.) 
This family is remarkable for the retention of two archaic 
characters: the large number of rays to the ventral fins and the 
duct between the air-bladder and the digestive tract; the latter 
character is, however, not universal, and has only been found in 
two genera (Beryx and Holocentrum). The scaling of the body 
varies greatly, and so does the development of the spines in the 
vertical fins. Several genera (Melamphaes, Anoplogaster, Trach- 
ichthys, ete.) have the head studded with large muciferous cavities 
which are covered with a thin skin. The vent is usually situated 
far behind the ventral fin, but in Paratrachichthys, a genus 
closely allied to 7rachichthys, 1t occupies a more anterior position, 
between the ventrals, whilst in Aphredoderus it shifts still further 
with age, opening on the throat in the adult. 
The Berycidae were abundantly represented in Cretaceous 
deposits by Beryz and other genera more or less closely related 
to living forms, and they appear to have been the precursors of 
other Perciform Fishes. About 70 species, referred to 15 genera, 
are known to live at the present day, mostly at great depths, in 
