LEUCISCUS ARRIGONIS. 181 



the body to the base of the caudal fin. The colour of the back is bluish- 

 green, with a metallic lustre, and the abdomen is silvery. 



The fish reaches a length of four and a quarter inches. It is found in the 

 southern parts of Spain and Portugal, in the tributaries and main waters of 

 the Guadiana, Guadalquivir, Genii, and the Guadiaro, near Gibraltar. 



Leuciscus macrolepidotus (STEINDACHNER). 



D. 10, A. 1011, V. 910. Scales: lat. line 3386, trans. 7/4|. 



This fish is limited to Portugal, where the name Raivaca is applied 

 indifferently to L. arcasii, and to it. The fin rays are alike, and the 

 form of the body is similar. The head is relatively larger in _Z/. macro- 

 lepidotus. The mouth is terminal and the upper jaw slightly overlaps the 

 mandible. There is an indistinct greyish band along the side. According to 

 Dr. Giinther, there are two and a half longitudinal series of scales between the 

 lateral line and ventral fin. It reaches a length of three to four inches. 



Professor Steindachner is disposed to regard this fish as a large-scaled 

 variety of L. arcasii, a conclusion which seems to be justified by his 

 specimens. 



Leuciscus arrigonis (STEINDACHNER). 

 D. 1011, A. 1113, V. 10, P. 1415. 



Q 



Scales : lat. line 46 52, transverse 



4^5. 



This Leuciscus has an elongated body, with the greatest height equal to 

 about the length of the head. The body is about five and a half times as long" 

 as the head. In the young fish the eye is relatively large, but in the mature 

 form it is one-fourth of the length of the head. The snout is rounded, and 

 projects a little beyond the mouth. The inter-orbital space is always wider 

 than the length of the snout, and increases in width with age, becoming 

 equal to one and two-thirds the orbital diameter. The cleft of the mouth is 

 curved, as in L. arcasii, and the angle of the mouth reaches back to the 

 orbital margin. 



There are six pharyngeal teeth in one row on the left side, and five on the 

 right. The dorsal fin is in the middle of the length, with its base equal 

 to two-thirds of the height of the fin. The ventral fin is opposite to the 

 dorsal, or slightly in advance of it ; its terminal edge is rounded. The base 

 of the anal fin is longer than that of the dorsal, but the height is less. The 



