796 
SCANDINAVIAN FISHES. 
is shorter with fewer rays“, the caudal less deeply 
forked, the silvery lustre not so bright, and the pec- 
toral, ventral, and anal fins sometimes 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 composed of 3 teeth, the regular 
number in the Rudd, and in the sharp median line of 
the ventral edge between the ventral fins and the anal 
aperture, 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 ( Spirlinus bipunctatus) ; and in the common 
Bleak too we sometimes find that the scales at the 
sharp ventral edge behind the ventral fins bend at an 
angle over the median line. In Scandinavian Bleak, 
however, three teeth have never been found in the 
outer pharyngeal row. 
The third of these forms was seen by Siebold 4 
in the fishmarket at Konigsberg. On the assumption 
that it is a hybrid between the White Bream and the 
Bleak, he gave it the name of Bliccopsis alburniformis. 
(Ekstrom, Smitt.) 
Genus SPIRLINUS. 
Beginning of the dorsal fin situated at a distance from the tip of the snout less than 3 times the length of the 
head. Length of the base of the anal fin less than l / 6 {between 16 and 18 %) of that of the body, and also 
less than that of the head. Pectoral fins shorter than the longest ray in the dorsal fin. Point of the lower jaw 
situated in a line with the the tip of the snout when 
situated in the anter 
These characters apply to only one known 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 
the mouth is closed. Scales thin and deciduous; nucleus 
ior half of the scale. 
referred the species to the genus Abramis. 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. 
a 15 branched rays. This number falls, however, according to Fatio, between the limits of variation in the Bleak (see above). 
6 Susswasserf. Mitteleur., p. 168. 
