360 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Suborder SQU AMIPINNES.- 1 The Scaly-fins. 
Body compressed, covered with small or minute ctenoid scales; lateral line unarmed, concurrent 
with the back; mouth small, with slender or brush-like teeth; opercles armed or not; nostrils double; 
gills 4, a slit behind the fourth; gill-membranes united to the broad scaly isthmus; pseudobranchiae 
present; air-bladder present; dorsal fin long, the spines usually well developed, the soft part usually 
more or less scaly; caudal usually truncate or double concave; anal similar to soft dorsal; ventrals 
thoracic, sometimes rudimentary, sometimes with 2 spines, the pubic bone becoming progessively elon- 
gate; vertebrae 10 + 14=24, but sometimes still further reduced. Basis of cranium double, with a double 
muscular tube; post-temporal trifurcate or bifurcate in Eplnppidx and the other transitional forms, as 
in the scombroids and percoids; in other species firmly united to the skull, its structure showing the 
usual 3 forks, the space between them filled by bone, so that only a foramen is left; second, third, and 
fourth upper pharyngeals small, usually reduced to vertical transverse laminae. Hypercoracoid with 
median foramen; pectoral with 4 short basal bones. This group comprises a large number of fishes, 
some of them showing analogies with the Carangidx on the one hand and with certain percoid fishes 
on the other; the typical forms specialized in directions leading toward the Plectognathi. The limits 
of the group are uncertain, although there is no doubt about the relationship of any of the genera here 
treated. Perhaps several of the families currently recognized as scombroid belong here. The Plectog- 
nathi are certainly descended from the Squamipinn.es. The close relation of Batistes to Hepatus admits 
of no doubt. This relationship is shown in the osteology, in the reduced post-temporal and coalesced 
bones of jaws, in the great development of the public bone, in the restriction of the gill-openings, and 
in the character of the scales, especially the armature of the tail. In a natural system the Balistidx 
would follow the Teuthididx and Siganidx. The Teuthididx and the Balistidx are as nearly related to 
each other as the Ephippidx are to the Chxtodontidx. 
a. Teeth small, not brush-like nor incisor-like; gill-membranes separate, free from isthmus. 
b. Ventrals I, 5 Antigonidx, p. 360 
bb. Ventrals I, 6 to I, 8 Zeidx , p. 361 
aa. Teeth elongate, brush-like or incisor-like; gill-membranes united to isthmus. 
c. Maxillary distinct; teeth brush-like, setiform, thick-set; post-temporal fully perforated by a foramen; pubic bone 
not greatly developed; caudal peduncle unarmed. Carnivorous fishes with short intestine. 
d. Scales well developed Chxtodontidx , p. 362 
dd. Scales reduced to minute asperities 1 Zanclidx, p. 381 
cc. Maxillary and premaxillary immovably united; teeth incisor-like, in a single series; post-temporal not fully per- 
forated by the foramen; pubic bones well developed; caudal peduncle usually armed with spines or tubercles. 
Herbivorous fishes with elongate intestine Acanthuridse, p. 383 
Family LXXI. ANTI GON ID/E. — Boar-fishes. 
Body compressed and elevated, covered with small, ctenoid scales; sides of head scaly; preorbital 
and preopercle more or less serrate or armed ; opercle small; gills normal; gill-membranes separate, 
free from isthmus; top of head bony; premaxillaries very protractile, the posterior process very long; 
mouth moderate, lower jaw projecting; teeth very small; lateral line not extending on caudal; dorsal 
fin long, the stout spines separated from the soft rays by a deep notch; dorsal spines not graduated; 
anal fin with 3 spines separated by a notch from the soft rays, the first spine longest; soft part of anal 
as long as soft dorsal; ventrals -i, 5, the spine strong, inserted below pectorals; caudal fin rounded, on 
a moderate peduncle; upper limb of post-temporal widened at its distal end, which affords a very 
firm attachment; lower limb short and thick; supraclavicle long and slender, its posterior edge 
sharply serrate, the serrations standing out above the surface of the skin; vertebras in normal number, 
10+13=23 (in Capros). Species few, arranged in 2 genera, living in rather deep water. Capros ctper, 
the boarfish, superficially resembles the John Dory, Zeus faber, and is common on the coasts of south- 
ern Europe. This family, like the preceding, is of doubtful affinities. It is only remotely allied to 
the Zeidse, and it has no relationship to the Carangidse or other scombroid forms. Antigonia bears 
much superficial resemblance to the Ephippidx, a resemblance doubtless arising from real affinity, as 
is shown by the form and attachment of the post-temporal. An extinct genus, Proantigonia, is said to 
connect Antigonia with Capros. 
