624 Series Plectognathi 
peculiarity gives the name of trigger-fish as well as the older 
name of Balistes, or cross-bow shooter. There are no ventral 
fins, the long pelvis ending in a single blunt spine. The numer- 
ous species of trigger-fishes are large coarse fishes of the trop- 
ical seas occasionally ranging northward. The center of dis- 
tribution is in the East Indies, where many of the species are 
most fantastically marked. JBalistes carolinensis, the leather- 
jacket, or cucuyo, is found in the Mediterranean as also on the 
American coast. Balistes vetula, the oldwife, oldwench, or 
cochino, marked with blue, is common in the West Indies, 
as are several other species, as Canthidermis sufjlamen, the 
sobaco, and the jet-black Melichthys piceus, the black oldwife, 
or galafata. Several species occur on the Pacific Coast of 
Mexico, the Pez Puerco, Balistes verres, being commonest. 
Still others are abundant about the Hawaiian Islands and 
Japan. The genus Balistapus, having spinous plates on the 
tail, contains the Jargest number of species, these being at the 
same time the smallest in size and the most oddly colored. 
Balistapus aculeatus and Balistapus undulatus are common 
through Polynesia to Japan. Most of the tropical species 
of Balistide are more or less poisonous, causing ciguatera, the 
offensive alkaloids becoming weaker in the northern species. 
Melichthys radula abounds in Polynesia. In this species great 
changes take place.at death, the colors changing from blue and 
mottled golden green to jet black. Other abundant Polynesian 
species are Nanthichthys lineopunctatus, Balistes vidua, Balistes 
bursa, and Balistes flavomarginatus. 
The File-fishes: Monacanthide.—Closely related to the Balis- 
tide are the Monacanthide, known as filefishes, or foolfishes. In 
these the body is very lfean and meager, the scales being 
reduced to shagreen-like prickles. The ventral fins are 
teplaced by a single movable or immovable spine, which is 
often absent, and the first dorsal fin is reduced to a single spine 
with sometimes a rudiment behind it. The species are in 
general smaller than the Balistide and usually but not always 
dull in color. They have no economic value and are rarely 
used as food, the dry flesh being bitter and offensive. The 
species are numerous in tropical and temperate seas, although 
none is found in Europe. On our Atlantic coast, Stephano- 
