7!»(5 



SCANDIX AV I A N FISHES. 



is shorter witli fewer rays", the caudal less deeply 

 forked, the silvery lustre not so bri<;lit, and the pec- 

 toral, ventral, and anal fins souietimes show a reddish 

 tinge. But the most convincing proof of its hybrid 

 nature lies, it is stated, in the outer row of pharyngeal 

 teeth, which is frequently coinjwsed of 3 teeth, the regular 

 number in the Kudd, and in the sharp median line of 

 the ventral edge between the venti'al tins and the anal 

 a])erture, which is generally covered by a row of bent 

 scales, but sometimes scaleless as in the Bleak. In the 

 last respect this form consequently resembles the follow- 



ing species (Spirliiiiis hipuiuiatiis); and in the common 

 Bleak too we sometimes find that the scales at the 

 sharj) ventral edge behind the \eiitral tins bend at an 

 angle over the median line. In Scandinavian Bleak, 

 however, three teeth have nevei- i)eeii found in the 

 outer pharyngeal row. 



Tiie third of these forms was seen by Siebold' 

 in the fishmarket at Konigsberg. ( )n the assumption 

 that it is a hybrid between the White Bream and the 

 Bleak, he gave it the name of BUccopsis alhurniformis. 



(EicsTROM, Smitt.) 



Genus SPIRLINUS. 



Beginnhiff of the dorsal fn situated at a itistanee from the tip of the snout less than 3 times the lene/th of the 

 head. Length of the l>ase of the anal fin less than ' ^ (hefiveen 16 and 18 %) of that of the body, and also 

 less than that of the head. Pectoral fins shorter than the lonflesf ray in the dorsal fin. Point of the lower jaw 

 situated in a line with the the tip of the snout when the mouth is closed. Scales thin and deciduous; nucleus 



situated in the anterior half of the sccde. 



These characters apply to onl)- one kno^vn species, 

 which is also so nearly allied to the preceding genus 

 that it was not separated therefrom until 1882 (by Fatio). 

 But this resemblance is coupled -with so close an ap- 

 proximation to forms treated of below that Gunther 



referred the species to the genus Ahramis. The generic 

 limitation is in many cases hardly more than a matter 

 of taste: its object here is among the genera to mark 

 the different stages in the gradual transition from the 

 Leuciscines to the Abramidines. 



15 branched rays. This number falls, however, according to Fatio, between the limits vi variatio 

 /. Mitteleiir., p. 168. 



in the Bleak (see above). 



