Series Plectognathi 415 
acanthus modestus, with deep-blue fins and the ventral spine 
immovable. Another is Stephanolepis cirrhifer, known as Kawa- 
muki, or skin-peeler. Alutera monoceros, and Osbeckia scripta, 
the unicorn fish, abound in the East Indies, with numerous 
others of less size and note. In the male of the Polynesian 
Amanses scopas (Fig. 347) the tail is armed with a brush of 
extraordinarily long needle-like spines. 
In Stephanolepis spilosomus the caudal fin is of a brilliant 
scarlet color, contrasting with the usual dull colors of these 
fishes. In Oxymonacanthus longirostris the body is blue with 
orange checker-like spots and the snout is produced in a long 
tube. About the islands of Polynesia, filefishes are relatively 
few, but some of them are very curious in form or color. 
The Spinacanthide.—In the extinct family Spinacanthide 
the body is elongate, high in front and tapering behind. The 
Fic. 348.—Common File fish, Stephanolepis hispidus (Linneus). Virginia. 
first dorsal has six or seven spines, and there are rough spines 
in the pectoral. The teeth are bluntly conical. Sprmacanthus 
blennioides and S. imperalis are found in the Eocene of Monte 
Bolca. These are probably the nearest to the original ances- 
tor among known scleroderms. 
The Trunkfishes: Ostraciide.—The group Ostracodermi con- 
tains the single family of Ostraciide, the trunkfishes or cuck- 
