400 
SCANDINAVIAN FISHES. 
The nostrils resemble those of the Plaice, both in 
form and position; but the anterior are somewhat more 
distinctly incised in an oblique direction at the top, 
and their pointed marginal flaps are somewhat longer 
and more distinct. The eyes are set on the left side, 
at least half as often, if not in quite so many cases, as 
on the right. Their position is the same as in the 
Plaice, but their size is less. In specimens between 
about 16 and 26 cm. long the longitudinal diameter of 
the eye is about 16 or 17 % of the length of the head, 
and in specimens between 29 and 32 cm. long about 
15 or 14 %. 
In this species also, the body is furnished with 
cycloid scales, imbricated only at the end of the tail 
and on the base of the caudal tin, and these smooth 
scales are more or less deeply imbedded in the thick 
skin. But their occurrence is confined, in ordinary 
cases, to the intervals between the spaces covered by 
sharp, spinous scales. Sometimes they are scarce, or 
may even be wanting on certain parts of the body. 
The spinous scales are either ordinary ctenoid scales, 
with spines only at the hind (free) margin, or trans- 
formed into spinous warts, with erect spines all round 
their surface. These scales or warts occur on both 
sides of the lateral line and on the head; but their 
number is very different in different specimens. In 
some cases they are scattered over the whole of the 
coloured side of the body, thickest, 'however, at the 
sides of the lateral line. On the blind side they ap- 
pear generally at the lateral line and seldom on the 
belly. The greater portion of the blind side of the 
head is always naked. At the base of each fin-ray, 
but set in the spaces between the roots of the rays, 
both in the dorsal and the anal fins, we find a large 
spinous wart. This row of warts seldom extends, 
however, to the end of the fin on the tail, and 
in most cases it is double on the anterior part of 
the body. In some cases the body is entirely smooth, 
with the exception of the spinous warts at the bases 
of the dorsal and anal fin-rays and a few on the 
head and at the lateral line. This is the case with 
the variety brought home from Archangel by Lieute- 
nant Sandeberg and described under the name of Pleuro- 
nectes Bogdanovii, of which equally typical specimens 
may be found in the Baltic. Among the varieties of 
flesus this form is evidently a deviation in the opposite 
direction to that taken among the varieties of platessa 
by pseudoflesus ; and thus the two species approach each 
other in their varieties. 
The lateral line, which begins at the bent, osseous 
ridge on the head, forms a curve that is often scarcely 
perceptible, above the pectoral fin, and then runs straight 
out to the extreme tip of the middle ray of the caudal 
fin. On an average we find 76 pores in this line on 
the body, and 26 on the caudal fin. 
The dorsal fin begins, as in the preceding species, 
above the upper eye, but ends at a distance from the 
caudal fin that may sometimes be equal to the least 
depth of the tail, and is at least 80 % thereof or 35 — 46 
% of the postorbital length of the head. The base of 
the dorsal fin as a rule occupies about 77 — 83 % (some- 
times as much as 86 %) of the length of the body to 
the base of the caudal fin. Its greatest height, which 
generally occurs between the 27th and 33rd rays (on 
an average at the 30th) from the beginning, is about 
13 — 16 % (on an average 14V 2 %) of' the length of the 
body minus the caudal fin. All the rays are simple 
and scalelessfi The anal fin, which is analogous to the 
dorsal in shape and structure, begins at a distance from 
the tip of the snout which, in our specimens, is never 
less than 40 % (in most cases between 41 and 46 %) 
of the length of the body to the base of the caudal 
fin. Its greatest height, which occurs between the 13th 
and 16th rays (on an average at the 15th), is generally 
somewhat greater than that of the dorsal fin * * * * * 6 ; but the 
length of its base is only seldom 60 % (generally be- 
tween 51 and 58 %) of the length of the body minus 
the caudal fin. The pectoral and ventral fins essentially 
correspond to those of the Plaice; but in the former 
the length of the first ray is more than half, or at 
least half, that of the second ray or even of the third, 
which is the longest. The caudal fin is of the same 
“ Nordmann (1. c.) states, however, with regard to the Black Sea form, that of 12 specimens 2 were furnished with “ciliated scales 
on the middle rays of the dorsal and anal fins.’ In two small specimens, respectively 13 and 14 dcm. long, which Hedenborg has sent 
home to Stockholm from the Bosphorus, the middle rays of the dorsal and anal fins are also rough with scattered, spiny scales. These spe- 
cimens are entirely destitute of ctenoid scales on the body with the exception of the usual row of spinous warts — and these are small — 
along the bases of the dorsal and anal fins, and the bony tubercles on the cranial osseous ridge between and behind the eyes. This ridge, 
by its extraordinary breadth behind, reminds us very much of the Arctic forms which we are just about to describe. 
6 In 12 full-grown specimens the greatest height of the anal fin measures on an average 1 5 x / 2 % of the length of the body minus 
the caudal fin. 
