Acanthopterygii; Synentognathi 425 
separate orders. Some of them are more related to the perch, 
others rather to ancestors of salmon or pike, while still others 
are degenerate offshoots, far enough from either. 
On the whole, all these forms, medium, extreme and tran- 
sitional, may well be placed in one order, which would include 
the primitive flying-fishes and mullets, the degraded globefishes, 
and the specialized flounders. As for the most part these are 
spiny-rayed fishes, Cuvier’s name Acanthopterygit, or Acanthoptert, 
will serve us as well as any. The Physoclysti of Muller, the 
Thoracices of older authors, and the Ctenorde: of Agassiz in- 
clude substantially the same series of forms. The order Teleo- 
cephali of Gill (redeos, perfect; xepadn, head) has been lately 
so restricted as to cover nearly the same ground. In Gill’s 
most recent catalogue of families, the order Teleocephal: in- 
cludes the Haplomi and rejects the Hemibranchu, Lophobranchit, 
Plectognatht, and Pediculatt, all of these being groups charac- 
terized by sharply defined but comparatively recent characters 
not of the highest importance. As originally arranged, the order 
Teleocephalt included the soft-rayed fishes as well. From it the 
Ostariophysit were first detached, and still later the Isospondyl 
were regarded by Dr. Gill as a separate order. 
We may first take up serially as suborders the principal 
groups which serve to effect the transition from soft-rayed to 
spiny-rayed fishes. 
Suborder Synentognathi.— Among the transitional forms be- 
tween the soft-rayed and the spiny-rayed fishes, one of the most 
important groups is that known as Synentognathi (cvv, to- 
gether; év, within; yvados, jaw). These have, in brief, the fins 
and shoulder-girdle of Haplomi, the ventral fins abdominal, the 
dorsal and anal without spines. At the same time, as in the 
spiny-rayed fishes, the air-bladder is without duct and the 
pectoral fins are inserted high on the side of the body. With 
these traits are two others which characterize the group as a 
suborder. The lower pharyngeal bones are solidly united into 
one bone and the lateral line forms a raised ridge along the 
lower side of the body. These forms are structurally allied 
to the pikes (Haplomz), on the one hand, and to the mullets 
(Percesoces), on the other, and this relationship accords with 
their general appearance. In this group as in all the remain- 
