244 
SCANDINAVIAN FISHES. 
worthy specific character. The definition of the species 
grounded on the size and number of the scales of the 
body is often liable to equally great uncertainty. True, 
the scales on the caudal region are arranged in fairly 
regular rows; but on the abdominal sides, in front of 
the second dorsal fin, they generally become smaller 
and smaller, and their arrangement more and more 
irregular, the nearer they are to the front part of the 
body. This sometimes renders it a matter of some 
difficulty to compute the number of scales in a line 
along the sides of the body. In the following table, 
by which it should lie possible to recognise the species 
which have hitherto been established and adopted as 
belonging to the Scandinavian fauna, and which is also 
intended to show their natural relationship, we have 
endeavoured, as far as possible, to avoid the employ- 
ment of such characters as may easily lead astray. 
However, as we shall now show, the question of the 
actual right of all these species to recognition is still 
unsolved. Several of them are founded on an insigni- 
ficant number of known specimens, and the variations 
of such “species” are far too little known to admit of 
their elucidation on scientific principles. 
A: Length of the peduncle of the tail at the 
upper margin® about ! / 2 that of the base 
of the second dorsal fin. Least depth of 
the tail more than 30 % of the length of 
the head. Six rays in the first dorsal 
fin. Vent situated in front of the middle 
of the body. 
a: Number of scales in a transverse row 
on the body at the beginning of the 
anal fin about 12, and in a row along 
the sides of the body about 40 Gobius niger. 
b: Number of scales in a transverse row 
on the body at the beginning of the 
anal fin about 7, and in a row along 
the sides of the body about 25 Gobius Friesii. 
B: Length of the peduncle of the tail at the 
upper margin about equal to the base of 
the second dorsal fin. 
a: Least depth of the tail more than 
30 °/ of the length of the head or than 
40 % of the length .of the peduncle 
of the tail at the upper margin. 
aa: Number of scales in a transverse 
row on the body at the beginning 
of the anal fin about 10 — 12, and 
in a row alone - the sides of the 
o 
body about 40. Vent situated in 
front of the middle of the body. 
a: Seven rays in the first dorsal fin Gobius flavescens. 
fj.\ Six (exceptionally five) rays 
in the first dorsal fin. 
aa: Longitudinal diameter of 
the eye less than -/ 5 of the 
distance from the first ray 
in the first dorsal fin to the 
first ray in the second ___ Gobius microps. 
ft(3: Longitudinal diameter of 
the eye more than 2 / 5 of 
the distance from the first 
ray in the first dorsal fin to 
the first ray in the second Gobius pictus. 
bb: Number of scales in a transverse 
row on the body at the beginning 
of the anal fin about 6 — 8, and in 
a row along the sides of the body 
25—30. 
a: Seven rays in the first dorsal 
fin. Vent situated in front of 
the middle of the body.. 
(3: Six (exceptionally five) rays in 
the first dorsal fin. 
aa: Vent situated behind the 
middle of the body 
(3(3: Vent situated in front of 
the middle of the body.. Gobius Jeffrey sii. 
b: Least depth of the tail less than 30 % 
of the length of the head or than 40 % 
of the length of the peduncle of the 
tail at the upper margin. Number of 
scales in a transverse row on the body 
at the beginning of the anal fin about 
12 — 14, and in a row along the sides 
of the body about 60. Six (exception- 
ally live) or seven rays in the first 
dorsal fin. Longitudinal diameter of the 
eye less than V 3 of the distance from 
the first ray in the first dorsal fin to the 
first ray in the second. Vent situated 
in front of the middle of the body... Gobius minutus. 
Gobius orca. 
Gobius scorpioides. 
Among - these recognised species we have first to 
distinguish the deep-water forms, with larger eyes, 
larger (more scattered) scales and more elongated (low) 
body. To this division belong Gobius Friesii , orca , 
scorpioides and Jeffrey sii, the last three of which we 
have been able to examine only in one solitary specimen 
the name of which could be fixed with certainty. With 
this exception, these four species are given here on the 
authority of other writers. We would also mention 
here that the distinction between Gobius microps and 
Gobius pictus has in many respects proved difficult to 
fix. Remembering the account we have given above 
of the variation in the number of the rays in the first 
dorsal fin, we consider it by no means improbable that 
future researches may show the connexion between these 
forms to be so close that the Scandinavian fauna at the 
present time really contains only five known species of 
the genus, precisely those which, as early as 1838, were 
Between the second dorsa] and the caudal fins. 
