96 THE FRESH-WATER FISHES OF EUROPE. 



smooth. The palate is covered with a white and very sensitive skin (Carp's 

 tongue). The nostrils of each side are separated by a projecting flap of 

 skin j the smaller hinder nostril is near to the eye. 



The beginning of the long dorsal fin is immediately over the ventral fin. 

 Both commence in front of the middle of the length. The base of the dorsal fin 

 measures one-third of the length of the fish. Its greatest height is about one- 

 third of its length ; but the height diminishes posteriorly, so that the last rays 

 are not half as long as the earliest. The first three or four rays, which are 

 undivided, are very short, and may be only one-third of the height of the 

 earliest-jointed ray. The third spinous ray, which is more flexible towards 

 the summit, carries on its hinder border on each side of a median furrow 

 a row of eleven to fourteen denticles, which increase in size from below 

 upward, and have their points directed downward. 



The anal fin is higher than long ; its termination is opposite to the 

 termination of the dorsal fin. Its bony ray (whose curved extremity is 

 often broken away in old fishes) is like those of the dorsal fin. The longest 

 rays />f the ventral fin are equal to those of the anal, and are never long 

 enough to reach so far back as the latter. The somewhat elongated pec- 

 toral almost reaches as far back as the ventral. The caudal fin has even lobes, 

 with rounded points. The longest caudal rays never exceed the length of the 

 head. 



The scales are large, thick, and make an approach to a four or five-sided 

 outline. The largest are in the anterior part of the sides ; their diameter 

 is equal to about one and a half times the diameter of the eye. Their 

 free, thick margin is often marked with a fan-like ornament. The lateral 

 line extends concavely, or nearly straight between the upper angle of the 

 operculum and the middle of the tail, and varies a little in position with age, 

 sex, and condition of the individual. In the lateral line an oblique or slightly 

 curved tube traverses the middle portion of each scale, which is similar in 

 form to the adjacent scales on the sides. The cephalic canals are marked on 

 the sub-orbital ring, where they are furnished with numerous tubes and 

 pores, which have thick walls, and extend along the branch of the pre- 

 operculum. All the branchial arches are covered with rake-teeth of nearly 

 equal length, and compressed sword shape, with their points turned inwards, 

 and their edges serrated. 



The back in its darkest parts is bluish-green ; the sides are yellowish 

 and greenish, and shade into the darker colour of the back. The abdomen 

 is whitish. Blackish spots often extend down from the lateral line. The 

 hinder edge of every scale is bordered with black, so as to form a dark 

 net-work over the fish ', or the pigment is sometimes more developed in 



