146 MICROPOGON UNDULATUS. 



the lips are thin ; the upper jaw is long and protractile ; the lower is shorter, and 

 received Avithin the upper when the mouth is closed, so as to leave some of its 

 teeth exposed. Both jaws are armed with rather broad bands of small, equal, villi- 

 form teeth. The middle pharyngeal bones are armed with larger teeth, sub-conical, 

 rounded at their apices, and paved ; in the others they are conical and pointed. 

 The tongue is short, thick, narrow, and placed far back ; the chin is furnished 

 with four pairs of minute barbels, and is indented with five water-pores. The pre- 

 opercle is serrated ; the serratures are small above, but are separated, and so long 

 at the angles as to resemble spines. The opercle terminates posteriorly in two 

 long and flat points, and is covered with scales. The sub-opercle is long, narrow, 

 and with a membranous prolongation behind. The inter-opercle is also long and 

 narrow, but is rounded below. The gill-openings are large, and have seven bran- 

 chial rays. 



The dorsal fin is single, though deeply emarginate, as the membrane that unites 

 the two portions is but slightly elevated ; it arises behind the root of the ventral, 

 and has in its anterior portion ten spines, the first of which is so short as to be 

 seen Avith difficulty; the second part has one spine and twenty-seven soft rays, 

 and is partially received in a groove of scales. The pectoral is broad, long, and 

 ends in a point opposite the fifth dorsal ray. The ventral is broad, but short ; it 

 begins behind the root of the pectoral, and ends about its posterior fifth, and has 

 one strong spine and five soft rays, the anterior of Avhich ends in a short delicate 

 filament. The anal is broad, and has two spines, the anterior minute, the poste- 

 rior large and strong, with eight soft rays, the second and third longest ; the other 

 rays gradually decrease in length, and thus make the posterior extremity of the fin 

 vertical. The caudal is rather long, and has seventeen rays. 



The scales represent the half of a circle, the diameter before, the circumference 

 behind, and finely ciliated ; the radical margin with twelve rather long strife, the 

 outer on each side largest. The lateral line is concvirrent with the back, and its 

 scales are smaller than those of the body, and marked with a tube that bifurcates 

 behind. 



