176 
SCANDINAVIAN FISHES. 
the third backwards and downwards and the lowest 
downwards and forwards. In most cases the points of 
all of them project above the skin, but sometimes the 
points of one or two of them are, as it were, broken 
off short, nodose or branched. They also vary consi- 
derably in direction and length. The opercular spine 
is almost hidden by the skin, flat and without any 
roughness whatever. On the suboperculum are 3 or 4 
fine, pointed spines, scarcely distinguishable, with the 
exception of the lowest, which is the longest. On 
the superior clavicular bones there are also two spines 
which are broad at the base and rough partly at the 
point and partly along the upper margin — the lateral 
line starts from these spines — and on the true clavicular 
bone a more pointed spine just above the pectoral fin. 
The cavernous bones of the face must also in some 
degree be regarded as a distinguishing peculiarity of this 
species. This character is, however, easily overlooked 
when the fish is examined during life or soon after its 
capture, for the thick, elastic skin conceals the depressions 
in the bones. It is more distinctly visible when the fish 
has been dead for some time or has been preserved in 
spirits. These depressions", which belong to the system 
of the lateral line, occur on the lower side of the lower 
jaw, three on each side; along the lower margin of the 
suborbital ring - — the chain of bones which forms the 
lower boundary of the orbit — to a number of four or 
five; and lastly in the margin of the preoperculum, 
which has a swollen appearance and in which there are 
two depressions above the uppermost spine and one in 
the interval between each pair of spines. 
As is generally the case in the Cotti, the body 
tapers in a conical form towards the tail. It shows less 
lateral compression than in the following species, but 
is also more elongated and shallower 6 . The lateral line 
is fairly straight. It consists of raised, oblong scales, 
concave at the end, and thus acquires a chain-like 
appearance. With this exception it is completely un- 
armed, and usually ends a little in front of the base 
of the caudal fin. Above the lateral line there are 
generally two irregular rows of scattered, round, some- 
what raised and rough scales, which are continued with 
one or two breaks, now in one row and now in the 
other, back to the caudal fin. On closer examination 
these scales show a porous surface, from the raised 
centre of which radiate small, granulate, bony lamellae. 
Similar scales, though of smaller size, also occur in no 
regular arrangement below the lateral line, where they 
begin just above the commencement of the anal fin 
and generally disappear at its end. 
The number of the branch iostegal rays varies in 
this species; it is most often six, but in some specimens 
five and in others seven. 
The dorsal fins are distinct and of ordinary form. 
The anterior generally contains eight rays; but the 
number varies between 7 and 9. All these rays are 
simple, not articulated and somewhat pungent, though 
more flexible and weaker than in the following species. 
The posterior dorsal fin generally contains 14 rays, 
sometimes 13, 15 or 16, all very rough and sharp on 
each side, articulated but not branched at the tip. In 
the anal fin we usually find 15 smooth, simple, arti- 
culated rays, but the number varies between 15 and 13. 
The pectoral fins contain from 15 to 17 rays, the 4th 
and 5th being the longest and the others gradually 
diminishing in size downwards, to such an extent that 
the last ray is extremely short, its length being only 
about 7 5 of that of the first or uppermost ray. All 
these rays are articulated and undivided, and some of 
them rough and sharp on each side, in 'which respect, 
however, sex generally causes some variation. In the 
female only the first ray is rough on the inside, while 
all the others are smooth; and on the outside only the 
first- ray is rough throughout its length, the second 
from the middle to the tip, the next ones, down to the 
5th and 6th inclusive, only at the tip, and all the rest- 
smooth. In the male, on the other hand, the first- 8 
rays are rough on the outside throughout their length, 
and the rest are also armed, when stripped of the thick 
skin which envelops them; and on the inside the first 
8 rays are rough at the point, the roughness extending 
to the middle of the 2nd and 3rd rays and gradually 
diminishing in extent as Ave proceed doAvn the fin. The 
ventral fins contain four rays, the first- a hard, spinous 
ray, Avhich is relatively longer than in the folloAving 
species of this genus, but is just as closely united as 
in them to the second ray, Avhich, like the next two 
(inner) rays, is soft- and articulated, but simple at- the 
tip. In the male the innermost ray is often consider- 
ably longer than the middle one, in the female of about 
the same length as it, but- to this rule, too, there are 
many exceptions. The caudal fin is more truncate than 
“ Cf. Acerina cernna, above. 
h Cf. the above scheme for the distinction of the species of this 
genus. 
