44 CENTROPRISTES ATRARIUS. 



seventh, eighth, and ninth prolonged to make the fin end in a point. The pec- 

 toral is rather large, broad, rounded posteriorly, and extends beyond the vent ; it 

 has eighteen rays. The ventral is broad and strong ; it begins with the pectoral, 

 and terminates in a point before the vent, and has one spine and five soft rays. 

 The anal arises nearly opposite the junction of the spinous and soft portions of the 

 dorsal fin, and has two spines, the anterior very short, and seven soft rays ; the 

 third and fourth are prolonged, and give a pointed form to the end of the fin. The 

 dorsal, pectoral, and anal fins are covered with scales for nearly one fourth of their 

 extent. The caudal has seventeen rays, and is trilobate when perfect, as the upper 

 and lower margins are prolonged, and the central portion is rounded and pro- 

 jecting ; this shape of the tail is not, however, always present ; when not, its 

 border is irregular. 



The scales are large, sub-pentagonal, rounded behind, and finely ciliated. The 

 lateral line is concurrent with the back, and runs along the upper third of the 

 body to the extremity of the origin of the dorsal fin, where it descends to the 

 median plane ; its scales are smaller than the others, sub-round, with the ciliated 

 portion prolonged, and more or less notched. 



Colour. The Black-fish presents some variety in its colour, but is in general 

 dusky-brown, or even bluish-black along the back. Each scale has a dusky mar- 

 gin, with a transparent spot in its middle, that allows the black skin to be seen 

 under it ; the dark margin in the scales below the lateral line is very small, and 

 consequently the sides and belly are of a much lighter colour than along the back, 

 where the transparent spot is but small. The head is dusky above, often tinted 

 with green or olive. The tongue is white, though the roof of the mouth and the 

 fauces both above and below are pale yellow. The membrane of the dorsal fin is 

 dusky, often with a bluish tint, and has several series of elongated spots of a pale 

 olive-colour or dirty white, which are so disjiosed as to make three longitudmal 

 interrupted lines in the spinous, and five in the soft portion. The anal fin is also 

 dusky, with similar lines, but less distinct and regular ; the other fins are more or 

 less dusky. 



