188 THE FRESH- WATER F I si IKS OF EUROPE. 



of the head, and the profile of the back is then flatter. When fully grown 

 the length of the head is to the length of the body as one to four and 

 five-sixths; and in the young the relative length is as one to four and a 

 half. The fish increases in thickness with age, and the thickness is at first 

 equal to half the length of the head, while in the adult it becomes two- 

 thirds of the length of the head, and the body is then nearly round. 

 The eye is placed in the anterior third of the head. The snout is 

 blunt. The mouth is oblique, and its angle extends back to below the 

 line of the orbital border. There is a wide interspace between the anterior 

 and posterior nasal apertures. The dorsal fin has short rays ; it commences 

 behind the middle of the body, and is higher than long. The anal fin is some 

 distance behind the vent, and is behind the end of the dorsal. Its base is 

 as long as that of the dorsal, but the fin is not so deep. The genital papilla 

 is placed in front of the anal aperture, and is wider and shorter in the female 

 than in the male. The ventral fin is small and fan-like. The pectoral fin is 

 larger and pointed. The caudal fin is deeply notched and evenly lobed. 



The course of the cephalic canal is defined by numerous pores, which form 

 white spots on the thick skin of the head, which is greenish-black or brown. 

 The back is dark green, with a metallic lustre. The scales have the aspect of 

 golden spots on a dark ground. The side of the body is paler; and the 

 abdomen is silvery with a yellowish tinge. The broad blue longitudinal 

 band, which extends along the middle of the side, coincides with the lateral 

 line only at its commencement and at its termination. 



This species is found only in the subterranean brooks and rivers of Croatia 

 which occasionally emerge from the rock. Its Croatian name is Piuri ; in 

 German it is called Grundel. 



GENUS : Tinea (CuviEii). 



The Tench type, which had been recognised under the generic name Tinea 

 by many of the earlier naturalists, was first accurately defined in Cuvier's 

 " Regne Animale." Its small scales are embedded deeply in the thick skin ; 

 the lateral line is incomplete. The fins are short ; the dorsal is opposite to the 

 ventral, and has no spine. The mouth has a barbel at its angle ; the lips 

 are moderately developed. There are short lanceolate gill-rakers, and rudi- 

 mentary pseudo-branchiae. 



The pharyngeal teeth are wedge-shaped, slightly hooked at the ends, in 

 a simple row, with five on the left side, and four or five on the right. 



