LETJCISCUS VULGARIS. 101 



in the anterior part of the body. The greatest height, in advance of 

 the dorsal fin, exceeds the length of the head, which is nearly one- 

 fifth of the entire length. The body has a compressed aspect, but the 

 greatest thickness is rather more than half the height. The head is rather 

 small, rounded above and flat at the sides. The mouth is small, with the 

 upper jaw wider than the mandible ; and the jaws do not perfectly meet, so 

 that, according to Giinther, a triangular interspace is included at the angle. 

 The angle of the mouth extends back as far as the nares. The length of the 

 head is four and a half times the diameter of the eye, and the eyes are separated 

 by one and a half times their own diameter. The dorsal fin is placed over the 

 ventrals in the middle of the body, and is conspicuously higher than long ; 



Fig. 80. LEVCISCUS VULGAKIS (FLEMING). 



its base is longer than the head, and the free margin is concave. The anal fin is 

 behind the dorsal, scarcely higher than long, with a base shorter than the 

 length of the head. The ventral fins are broad and well-developed ; the pec- 

 toral fins are rather longer. The caudal fin is strong, evenly-lobed, and as 

 long as the head. The lateral line descends in a regular concave curve. 



The scales are very similar to those of the Chub ; they are rather higher 

 than long; measure one-third the diameter of the eye in the young fish, and 

 four-fifths the diameter of the eye in the adult. Each has the posterior border 

 somewhat truncated, with the upper and lower angles concavely excavated. 



In life, the colour resembles polished steel ; the back and upper part of the 

 head, and the dorsal and caudal fins, may be black or steel-blue. The sides are 

 silvery, often with a bluish tinge. The pectoral and anal fins are pale red, and 

 the anterior part of the former may be spotted with orange ; the iris is green, 

 yellow, and red. 



The Dace frequents tranquil tributary streams and brooks, preferring 

 11 



