804 
SCANDINAVIAN FISHES. 
the Systema Naturce. This is evident from the appended note in the 
Fauna, where Linnaeus expressly states that he had counted 35 rays 
in the anal fin of the Bjorkna ■ — a number which, among the species 
indigenous to Sweden, is to be found in Abramis ballerus alone. In 
Retzids’s edition of the Fauna Suecica the error was not corrected, 
although Bloch had already given a lucid description and a good 
figure, considering the date at which it was executed, of Artedi’s 
species, under the name of Cyprinus Blicca . which it still retains. 
Nilsson was the first Scandinavian writer to restore the name of 
Bjorkna to its original signification, and to recognise Bloch’s nomen- 
clature (see Prodr. Ichth. Scand.); but Ekstrom had previously (Vet. - 
Akad. Handl. 1830) expressed the same opinion on the strength of 
information privately supplied to him by Nilsson. 
The White Bream is the smallest Scandinavian 
member of the genus Abramis. It never attains any 
considerable size. Its ordinary length is between 15 
and 23 cm., rising, however, sometimes to 30 or, in 
exceptional cases, 35 cm., including the whole of the 
caudal fin. 
In most respects the White Bream comes nearest 
our common Bream, and in appearance so closely re- 
sembles young Bream that it is frequently confounded 
with them, under the common name of Braxenpanka. 
In our description we shall therefore lay special stress 
on the differences brought to light by a comparison 
between them. 
In the form of the body it is hardly possible to 
detect any constant difference between the White Bream 
and the Bream. The body of both is compressed and 
deep, though generally a little less so in the former. 
In White Bream preserved in the Royal Museum, and 
measuring between 106 and 239 mm. in length to 
the end of the middle rays of the caudal fin, the great- 
est depth of the body is between 31 % (in young spe- 
cimens) and nearly 40 % (in old) of its length, and the 
greatest thickness (with more individual variations) be- 
tween V 3 and V4 of' the greatest depth. The least depth 
of the tail increases during these changes of growth 
from 9‘4 to 11*3 % of the length of the body. The 
back, which rises somewhat abruptly from the occiput, 
then ascends in a regular curve to the beginning of 
the dorsal fin, where it forms an obtuse angle, and 
afterwards slopes almost in a straight line to the caudal 
fin. Though carinated from the occiput to the dorsal 
fin, it is thicker and more convex than in the Bream. 
The belly is flat from the pectoral region to the vent- 
ral fins. From this point to the vent it is sharply 
carinated. The ventral profile is almost straight from 
the pectoral region to the anal aperture, where it- forms 
an obtuse angle, more acute, however, than the dorsal 
angle, and advances in a somewhat incurved line to 
the caudal fin. 
The head, the length of which is about 1 / 5 (21 x / 2 — 
20 %) of that of the body, tapers uniformly forwards 
from above and below, but the snout is fairly thick and 
obtuse, projecting a little beyond the mouth. The fore- 
head is broad and convex, the breadth of the inter- 
orbital space being about 77 2 — 8 % of the length of 
the body, or 357 2 — 387 2 % of the length of the head. 
The frontal profile is straight from the occiput to the 
nostrils, where it descends abruptly, and slopes towards 
the snout. The sides of the head are moderately com- 
pressed, the thickness being equal to the depth, mea- 
sured at the anterior orbital margin. The mouth is 
small and ascends only slightly, but may be projected 
to some distance in a tubular form. The corner of the 
mouth falls short of the perpendicular from the anterior 
orbital margin. The length of the snout, which mea- 
sures about 5 — 6 % of that of the body or about 23 — 
31 % of that of the head, is as a rule equal in young 
specimens to the length of the upper jaw (from the tip 
of the snout), in old a little greater. The length of 
the lower jaw measures about 6 x / 2 — 7 % of that of the 
body, or about 32 — 34 % of that of the head, is less 
than that of the suture between the suboperculum and 
operculum, and also than 71 % (in the said specimens 
70 — 57 %) of the least depth of the tail. The eyes, 
on the other hand, are comparatively larger than in 
the Bream, their longitudinal diameter varying in our 
specimens between about 34 and 27 % of the length of 
the head, while in young specimens it is perceptibly 
greater, in old slightly less, than the length of the snout. 
Their size is often so considerable that the White Bream 
may be at once distinguished thereby from the young 
Bream in its company. The position of the eye is such 
that the postorbital length of the head in young spe- 
cimens is less, in old somewhat more, than half its 
entire length. The nostrils are set much as in the 
Zarthe, the distance between the posterior nostril and 
the upper anterior part of the orbital margin being 
about 7s °f that between the anterior nostril and the 
tip of the snout. The anterior nostril is smaller than 
the posterior, but circular; while the latter is obliquely 
set and elliptical or crescent-shaped. The gill-openings 
are smaller than in the Zarthe, the branchiostegal mem- 
branes coalescing below with the isthmus at a greater 
distance from, each other and farther back, in a line 
with the hind (vertical) margin of the preoperculum. 
