ACANTHROPTEIIYGII. 203 



length. The ventrals consist of a long filament dilated near the extremity. 

 They are also found in India. 



STYLEPHORUS, Sharv. 



A vertical caudal, as in Gymnetrus, but shorter ; the extremity of the tail, 

 instead of being curved into a small hook, is prolonged into a slender cord 

 longer than the body. But one specimen is known. 



In a third tribe the snout is short, and the mouth cleft obliquely. 



CEPOLA, Linnceus. 



A long dorsal and anal, both reaching to the base of the caudal, which is 

 tolerably large ; no rise in the cranium ; snout short ; lower jaw curved 

 upwards ; the teeth prominent, and the ventrals sufficiently developed. 



LOPHOTES, Giorna. 



A short head, surmounted with a high osseous crest ; to whose summit a 

 long and stout spine is articulated, bordered behind with a membrane and a 

 low fin, whose rays are nearly all simple, extending from this spine to the 

 point of the tail, which has a distinct, but very small caudal. 



FAMILY IX. 



THEUTYES. 



OUR ninth family is as closely allied to the Scomberoides as the preceding 

 one, but in other points, such as the armature, which is found in several 

 genera on the sides of the tail, or in others, the horizontal spine before the 

 dorsal, &c. It contains but very few genera; they all have a compressed, 

 oblong body ; a small mouth, but slightly or not at all protractile, each jaw of 

 which is armed with a single range of trenchant teeth ; palate and tongue 

 without teeth, and a single dorsal. They are herbivorous, feeding on fucus 

 and other marine plants. 



SIGANUS, Forsk. 



These fishes have a remarkable character unique, in icthyology in their 

 ventrals, which are furnished with two spinous rays, one external, the other 

 internal; the three intermediate ones branching as usual. They have five 

 branchial rays, and a horizontal spine before the dorsal. The styloid bones of 

 their shoulder curve as they lengthen, so as to unite at their extremities with 

 the first interspinal of the anal. Numerous species are found in the Indian 

 Ocean. 



The remaining genera are Acanthurus (Sturgeons), Prionurus, Naseus, 

 Axinurus, and Priodon. 



