886 
SCANDINAVIAN FISHES. 
in young specimens and the females) it is of fairly 
uniform height or highest in the anterior part (the 
6th — 8th ray), the height being about 11 — 14 % of the 
length of the body. Sometimes again (at least in old 
males) the posterior part of the tin (the 16th — 21st ray) 
rises to a height of as much as 7 4 of the length of 
the body. The adipose fin is of the same shape as in 
the Salmons, forming a curved lobe of fairly uniform 
breadth. It lies nearly vertically above the end of the 
anal fin, the distance between it and the first upper 
supporting ray of the caudal fin being about Vs — V9 
of the length of the body. The anal fin also resembles 
that of the Salmons. It begins at a distance from the 
tip of the snout (the articular knobs of the maxillaries) 
which measures on an average about 71 % of the length 
of the body. The length of its base is 8 — 9 % (ex- 
ceptionally 7 or 11 %\ and its greatest height (the 
length of the first or second branched ray) during youth 
about 8 — 10 %, in old females about 10—11 %, and in 
old males sometimes 1 3 1 / 2 %, of the length of the body. 
Its hind inferior margin is convex. The caudal fin is 
deeply forked, with pointed lobes. Its middle rays, 
the relative length of which decreases with age from 
about 7 to 4 % of the length of the body, always 
measure less than half, sometimes only one-third, of 
the length of its longest rays. 
The pectoral fins are set low, with almost hori- 
zontal base. They are obliquely pointed, and their 
length is about 14 — 17 % of that of the body. The 
ventral fins are as a rule somewhat shorter, but some- 
times even longer, than the pectoral. They are also 
broader and more obtuse. The distance between them 
and the tip of the snout (the articular knobs of the 
maxillaries) is about 46 — 48 % of the length of the 
body. The preabdominal length is on an average 28 %, 
the postabdominal length 26 %, of the length of the body. 
The scales are most like those of the Cyprinoids, 
both in texture and shape. They are not only larger 
(fewer), but also thicker than those of the Salmons, 
and are furnished with radiating grooves. These are 
especially deep in the anterior (inserted) part of the 
scale, to which part they give an undulating appearance, 
and the truncate margin of which they render sinuate, 
forming 3 — 5 indentations. They are very short at the 
posterior, rounded margin of the scale, where they leave 
only slight notches. The lateral line follows a fairly 
median course, in front somewhat nearer to the back 
than to the belly. The middle part of its scales pro- 
ject. at the inserted margin in a rounded form. The 
ordinary scales cover the whole body, but leave most 
of the fins, the head, and a greater or less portion of 
the breast naked". The base of the caudal fin is, how- 
ever, clothed with smaller and thinner scales, and this 
covering follows the caudal rays, especially the longest 
ones, the scales here growing gradually smaller outwards 
and being of a linguiform shape, calling to mind in their 
structure the scales we have seen above in Mall of us. 
Its varied and shifting colours render the Gray- 
ling a handsome fish. Dark and light phases of colour 
follow with different environments, and the Grayling, 
like so many other fishes, has a particular festal dress. 
The ground-colour of the back is brown or grayish, 
shading into blue, green, or a purplish lustre in dif- 
ferent lights. The sides are lighter, those of the head 
with a metallic lustre, those of the body with a silvery 
lustre or a tinge of yellow. The belly is of a more 
or less pronounced silvery white. Along the sides of 
the body, between the back and belly, run a number (up 
to 16) of dark, parallel stripes, marking the limits be- 
tween the regularly arranged rows of scales; and be- 
sides there lie sharply defined, dark spots, reminding 
us of the coloration of the Salmons, irregularly scat- 
tered on the sides of the head and varying in occur- 
rence, but sometimes distributed in longitudinal rows, 
especially on the forepart of the sides. The fins of the 
ventral side are yellowish or ashy gray at the base 
(sometimes throughout), towards the top (especially the 
posterior ones) violet. The caudal fin, as well as the 
adipose fin, is bluish gray, violet, or even of the same 
dark hue as the back. Most prominent is the coloration 
of the large dorsal fin, which is of an iridescent violet 
or lake, with three or four rows of dark, quadrangular 
spots, generally ocellated in lake, on the fin-membrane 
between the light rays. In the spawning-dress all these 
colours are heightened, and the body gleams with a 
golden lustre. 
The peritoneum is white. The short oesophagus 
passes into a very thick-walled stomach * * * 6 , which extends 
" At the median line the belly is usually covered with scales (even if these are only small) forward to a line with the insertion of 
the pectoral fins; but on each side and in front throughout the whole ventral side the skin is naked. The variations in the extent of this 
scaleless part led Valenciennes to establish the species gymnothorax and gymnogaster. 
6 In a male 55 cm. long the wall of the stomach is 6 mm. thick. 
