CHAPTER XXX 
BERYCOIDEI 
WHE Berycoid Fishes.— We may place in a separate 
ee x J order a group of fishes, mostly spiny -rayed, which 
: appeared earlier in geological time than any other 
of the spinous forms, and which in several ways represent the 
transition from the isospondvlous fishes to those of the type of 
the mackerel and perch. In 
the berycoid fishes the ventral 
fins are always thoracic, the 
number of rays almost always 
greater than I, 5, and in all 
cases an orbitosphenoid bone 
is developed in connection 
with the septum between the 
Fig. 367.—Skull of a Berycoid fish, Beryx orbits above. This bone is 
splendens Cuy. & Val., showing the or- found in the Tsospondyli and 
bitosphenoid (OS), characteristic of all 5: 02 Ono 
Berycoid fishes. other primitive fishes, but ac- 
cording to the investigations 
of Mr. E. C. Starks it is wanting in all percoid and scombroid 
forms, as well as in the Haplomi and in all the higher fishes. 
This trait may therefore, among thoracic fishes, be held to define 
the section or suborder of Berycordez. 
These fishes, most primitive of the thoracic types, were more 
abundant in Cretaceous and Eocene times than now. The 
possession of an increased number of soft rays in the ventral 
fins is archaic, although in one family, the Monocentride, the 
number is reduced to three. Most of the living Berycoidez 
retain through life the archaic duct to the air-bladder char- 
acteristic of most abdominal or soft-rayed fishes. In some 
however, the duct is lost. For the first time in the fish series 
the number of twenty-four vertebre appears. In most spiny- 
465 
