440 FISHES. 



ceedingly compressed. No scales are developed, but the 

 skin forms numerous oblique parallel folds. The gill-cover 

 and the breast are shining silvery. 



Naseus. — Tail with two (rarely one or three) bony keeled 

 plates on each side (in the adult). Head sometimes with a bony 

 horn or crest-like prominence directed forwards. Ventral fins 

 composed of one spine and three rays. From four to six spines 

 in the dorsal ; two anal spines. Scales minute, rough, forming a 

 sort of fine shagreen. Air-bladder forked behind. Intestinal 

 tract with many circumvolutions. 



Twelve species are known from the tropical Indo-Pacific, 

 but none of them extend eastwards beyond the Sandwich 

 Islands. In their mode of life these fishes resemble the 

 Acarithuri. Likewise, the young have a very different appear- 

 ance, and are unarmed, and were described as a distinct 



Fig. 194. — Naseiis imicornis. 



genus, Kcris. One of the most common species is N. unicor- 

 nis, which, when adult (22 inches long), has a horn about 

 2 inches long, whilst it is merely a projection in front of the 

 eye in individuals of 7 inches in length. 



Prionurus is an allied genus with a series of several keeled 

 bony laminte on each side of the tail. 



Second Family — Carangid.e. 



Bodi/ more or less compressed, oblong or elevated, covered with 

 small scales or naked ; eye lateral. Teeth, if present, conical. 

 No lony stay for the prmopcrcnlum. The sjnnotcs dorsal is less 

 developed than the soft or than the anal, either continuous with, 

 or separated from, the soft portion ; sometimes rudimentary. 



