46 THE FRESH-WATER FISHES OF EUROPE. 



caudal ; both are somewhat shorter than the rays of the ventral fins. The 

 anal aperture is half-way down the length of the body. 



The scales are small, hard, and have their margins finely denticulated : the 

 lateral line contains ninety scales, and at the commencement of the first dorsal 

 fin there are seven rows of scales above the lateral line, and thirteen to fourteen 

 rows below it. Towards the tail the lateral line descends, so as to occupy a 

 lower position, and beneath the second dorsal fin it runs along the middle of 

 the side of the body, and has eight or nine rows of scales above it. The throat 

 is for the most part naked, but scattered groups of scales are found here and 

 there. Small scales cover the base of the pectoral fin, and behind the ventral 

 fin the belly is entirely covered with scales. The system of cephalic canals is 

 conspicuously developed, and forms, with the upward branch of the pre- 

 operculum, a wide, deep channel, which is covered by six thin bony plates, 

 which are indicated by as many depressions in the skin which extends over 

 them. The accessory gills are small and comb-shaped; and the b ranch iostegal 

 rays are seven in number, as in the other species of the genus. 



The back is greenish-brown, the sides are yellowish or grey-yellow, and the 

 belly whitish. Irregular spots and dark-brown marbling extend across the 

 four cloudy brownish-black bands, which are more or less conspicuous, and run 

 obliquely from front to back down the sides. The first band descends in front 

 of the first dorsal, and extends below its base, the second band is under the 

 hinder half of the same fin, the third and fourth bands similarly descend from 

 the beginning and the end of the second dorsal fin. The snout and operculum 

 are brownish, and irregular oblique blackish streaks occur on the cheeks. 



This fish often reaches a length of one foot, and a weight of two pounds, 

 and thus grows to a much larger size than the Aspro vulgar is. Its flesh is 

 agreeable to the palate, and is easily digested. 



The species belongs to the basin of the Danube, and only visits the larger 

 tributary streams. It has been found in the Salzach, and Alt, in the Sieben- 

 biirgen. Like the other species, it spawns in May. It feeds chiefly on worms, 

 larva?, and small fishes. It lives for seven or eight years, and is well 

 defended from all enemies, except the Pike, by its rough scales and sharp 

 spines. 



Aspro vulgaris (Cuvioi AND VAL.). The Apron. 



This species (Fig. 17), originally defined by Cuvier and Valenciennes, and 

 commonly known as the Apron, was confounded with the Streber until Von 

 Siebold separated them. It is characterised by having nine spinous rays in 

 the first dorsal fin, with thirteen rays in the second dorsal, of which the first 



