ACANTHOPTERYGII. 205 



MONOCENTRIS, Bl. >chn. 



A singular genus; the body is short, thick, and completely mailed with 

 enormous angular, rough, and carinated scales; four or five stout free spines 

 supply the place of the first dorsal; each ventral consists of an immense 

 spine, in the angle of which a few soft and almost imperceptible rays are 

 concealed; head bulky and mailed; front gibbous; mouth large; short crow- 

 ded teeth in the jaws and palatines, but none in the vomer; eight rays in the 

 branchiae. But one species is known; the 



Mon. japonica, Bl. Schn. Six inches long, of a silvery white. From the 

 sea of Japan. 



After this family we place the 



OREOSOMA, Cuv. 



A small oval fish, whose whole body, above and beneath, is studded with 

 thick cones of a heavy substance. There are four of them on the back, and 

 ten on the belly, arranged in two series, with smaller intermediate ones. 

 It was discovered in the Atlantic, by Peron. 



FAMILY III. 



SCIENOIDES. 



This family is closely related to the Percoides, and even presents 

 nearly similar combinations of external characters, particularly in the 

 indentations of the preoperculum, and in the spines of the opercu- 

 lum; but both vomer and palatines are without teeth; the bones of 

 the cranium and face are generally cavernous, and form a muzzle 

 more or less gibbous. The vertical fins are frequently somewhat 

 scaly. 



Some of the Scienoides have two dorsals, and others have but 

 one; among the former we first find the genus, 



SCLENA. 



Whose common characters consist of a gibbous head, supported by caver 

 nous bones, two dorsals, or one deeply emarginate, whose soft part is 

 much longer than the spinous; a short anal, a dentated preoperculum, an 

 operculum terminating in points, and seven branchial rays. If it were not for 

 the absence of the palatine teeth, these fishes would resemble the Perches. 

 Naturalists divide it into various subgenera. Some of the species, such 

 as the King-fish (an Umbrina) inhabit the American seas. 



The Scienoides, with a single dorsal, are subdivided according to 

 the number of their branchial rays. 



