FISHFS OF HAWAIIAN ISLANDS. 
407 
skeleton imperfectly ossified, the number of vertebra - * usually small, typically fewer than 24 (usually 
14 to 20), rarely considerably increased, (rill-openings restricted to the sides; ventral fins reduced 
or wanting, the pelvic bones usually elongate; spinous dorsal small or wanting; air-bladder without 
duct. Fishes chiefly of the Tropics, mostly inactive and depending on their tough skin or bony or 
spinous armature for their protection. 
a. Jaws with distinct teeth. 
b. Spinous dorsal present; body with scales or movable plates... Sclerodermi, p. 107 
hb. Spinous dorsal wanting; body encased in an immovable carapace of hexagonal plates; the jaws, bases of tins, and tail 
only free. Ostracodermi, p. 411 
aa. Jaws modified into a sort of beak, each with an enamel-like covering and without distinct teeth; scales rhomboid or 
spifliform, with root-like insertions; spinous dorsal wanting. Gymnodontes, p. 424 
Suborder SCLERODERMI. 
The Sclerodermi may be defined as Plectognathous fishes with a spinous dors?., composed of one 
or more spines inserted just behind the cranium; body of the normal fish-like shape; scales rough, or 
spinigerous, of regular form; jaws with distinct teeth, conical or incisor-like. 
a. Ventral fins obsolete, or the pair represented by a single spine at the end of the long pelvic bone; scales rough, rhombic, 
or spiniform. 
6. Vertabne in small number, 17 to 21; no barbel at chin: gill-opening not before the eyes. 
c. First dorsal composed of 3, rarely 2, spines; the first spine very large, the second locking it in erection; scales com¬ 
paratively large, bony, rough, forming a coat of mail; vertebrae 17. lialistidse , p. 407 
cc. First dorsal of a single spine, with a rudiment at its base; scales minute, not bony, the edges spinescent, so that the 
surface of the body is rough velvety; vertebras is to 21. Monacanthidic , p. 418 
Family LXXVI. BALISTID4E. -Trigger-fishes. 
Body oblong or ovate, moderately compressed, covered with rather large, rough scales or scutes 
of various forms, not forming an immovable carapace; lateral line obscure or wanting; mouth, small, 
terminal, and low; jaws short, each with about 1 series of separate, incisor-like teeth; eye near occiput; 
preorbital very deep; no barbels; gill-openings small, slit-like, above or in front of pectoral fins, not 
before eyes; dorsal fins 2, the anterior of 2 or 3 spines, the first highest and very strong, the second 
locking it in erection; second dorsal remote from the first, of many soft rays. Shore fishes of the 
tropical seas, of rather large size, carnivorous or partly herbivorous, very rarely used as food, many of 
them reputed to be poisonous. 
a. Caudal peduncle compressed. 
b. Teeth white or pale, not red. 
c. Teeth unequal, oblique, each one deeply notched. 
d. Gill-opening with a number of enlarged bony plates or scutes behind it; ventral flap movable, supported by a 
scries of spines, more or loss free at tip and resembling tin rays; cheeks entirely scaled, without naked 
grooves or patches. 
c. Eye with a preocular groove . Ha listen, p. 407 
cc. Eye without preocular groove; caudal scales spinous . Baltetapws, p. 413 
dd. Gill-opening with only ordinary scales behind it. 
lu Chin not projecting; cheeks closely scaled; dorsal spines scales of posterior parts unarmed or keeled 
. Canthidermis , p. 415 
hh. ('hiii much projecting; cheek with 3 to 5 narrow parallel grooves; dorsal spines 2; scales of posterior parts 
more or less keeled. Xanthichihys, p. 416 
cc. Teeth even, ineisor-like. Jfelichthys, p. 117 
Genus 184. BALISTES (Artedi) Linnaeus. Trigger-fishes. 
Body compressed, covered with thick, rough scales or plates of moderate size, 30 to 80 in a length¬ 
wise series; a naked groove before eye below nostrils; lateral line more or less developed, very slender, 
undulate, conspicuous only when the scales are dry, extending on the cheeks; pelvic flap large, mov¬ 
able, supported by a series of slender, pungent spines; caudal peduncle compressed, its scales armed 
or unarmed, with or without spines or differentiated tubercles similar to those on rest of body; gill¬ 
opening with enlarged bony scutes behind it; cheeks entirely scaly, without naked patches or grooves; 
each jaw with irregular, incisor-like teeth, usually 4 on each side in each jaw; first dorsal of 3 spines, 
the anterior of which is much the largest, the second acting as a trigger, locking the first when erected; 
