SALMON. 



The vignette above represents the form of the different 

 parts of the gill-cover in the three species just named ; 

 of which the figure on the left hand is that of the Salmon, 

 the middle one is the gill-cover of the Bull-Trout, and 

 that on the right hand is the gill-cover of the Sea or 

 Salmon Trout : the differences are immediately apparent 

 when thus brought into comparison. 



In the Salmon, the posterior free edge of the gill-cover, 

 as shown in the left-hand figure, forms part of a circle ; 

 the lower margin of the suboperculum is a line directed 

 obliquely upwards and backwards : the line of the union 

 of the suboperculum with the operculum is also oblique, 

 and parallel with the lower margin of the suboperculum ; 

 the interoperculum is narrow vertically, and its union with 

 the operculum is considerably above the line of the junc- 

 tion between the suboperculum and the operculum. The 

 teeth of the Salmon are short, stout, pointed, and re- 

 curved : as stated in the generic characters, they occupy 

 five situations at the top of the mouth ; that is, a line of 

 teeth on each side of the upper jaw, a line on each palatine 



