698 
SCANDINAVIAN FISHES. 
side of the angle of the clavicle. When the spinous 
ray is erected, it is simultaneously twisted in a forward 
and downward direction — the result of the above- 
mentioned oblique position of one of the two articular 
surfaces on the scapulo-coracoid bone — and during this 
twisting process the last-mentioned, pulley-shaped knob 
rubs against the wall of the clavicular groove — thus 
producing the creaking noise — until this articular knob 
is so firmly wedged in the lower end of the groove that 
the ray cannot be bent without being twisted back at 
the same time. Another consequence of the erection of 
the spinous ray is that the insertion of the fin, which 
previously occupied an oblique position, in a backward 
and downward direction, now becomes horizontal. The 
other rays of the pectoral fins are repeatedly branched, 
the first being sometimes twice as long as the spinous 
ray, the first (uppermost) three or four gradually in- 
creasing in length, the lower ones from this point very 
gradually decreasing in length down to the last two or 
three, which grow rapidly shorter, one after another. 
The last ray is not even half so long as the spinous ray. 
The entire length of the fins, from the upper angle of 
the insertion to the tip of the longest ray, is in our 
males more, in our females less than 2 / 3 of the length 
of the head". 
The ventral tins are of a broad oval shape. Their 
first ray is simple but short. They are inserted at about 
the end of the first third of the body, so far back that 
the distance between the dorsal fin and the tip of the 
snout measures only about 75 — 70 % (in young speci- 
mens 80 %) of the distance between the ventral fins and 
the same point. Their length is in the males more, in 
the females less than 2 / 5 of the length of the head * 6 . 
The pelvic bones are of a shafted spade-shape, with the 
outer posterior margin forming an arc. They meet each 
other partly in a fairly firm suture between the pos- 
terior (extended) parts, partly in a ligamentous con- 
nexion between the anterior ends. 
The lateral line follows a straight course along the 
middle of the sides of the tail (sometimes a little higher, 
sometimes lower), but in front it rises in a greatly elong- 
ated arch up to the temporal region, and may often 
be traced distinctly in a straight line across the cheek 
below the eye, as shown in our figure. The slimy 
a In the former 72 — 81 %, in the latter 54 — 55 % of the li 
6 ii ii ii 48 53 %, ,, ,, ,, 34 36 % ,, ,, 
c In a male nearly 2 metres long the total length of the 
pylorus and the bottom of the stomach about 1 dm. 
surface of the skin, as we have mentioned above, is 
entirely scaleless. 
The coloration seems to vary considerably according 
to local circumstances. The ground-colour is above 
olive-green, below white. The back is always darker, 
sometimes shading even into black. The sides are ir- 
regularly spotted (mottled), in light specimens with 
large and distinct spots of the dark colour of the back 
on the ground-colour of the belly, which grows lighter 
and lighter below. The dorsal fin is of the same dark 
colour as the back, olive-greenish or black. The other 
fins in common repeat the coloration of the body, the 
base bearing the colour of the back, the margin or outer 
part that of the belly. Such was at least the appearance 
of the large Sheatfish, a male, from which our figure 
is taken. It reached Stockholm alive, and was kept alive 
while the artist painted it. But as its strength began 
to fail, the lighter parts, especial])' of the pectoral, ven- 
tral, and anal fins, became more and more suffused with 
blood, and finally, when the fish was in a moribund 
state, blood oozed in drops from the margins of these 
fins. The maxillary barbels are on the upper side of 
the same colour as the back, underneath paler or even 
of the same colour as the belly. During life the outer 
parts of the eyes were blackish blue, the inner parts 
lighter blue, with the iris yellow but punctated with 
dark dots and set off by a sharply-defined, yellow inner 
margin from the pupil, which was black. 
The length of the abdominal cavity measures in 
young Sheatfish about 1 / 3 , in older ones about 1 / i of 
that of the body. The peritoneum is white. The oeso- 
phagus is continued straight backwards by the large and 
muscular stomach, the pointed or rounded bottom of 
which lies almost above the middle of the length of the 
pelvic bones. Rather far forward, at about the middle 
of the stomach and on its under surface, the pyloric 
part projects in a forward direction. This part is bounded 
from the intestine by a more or less strong contraction, 
and internally divided from the same by a valve". The 
duodenum, which is without appendages, is of about 
the same thickness as the pyloric part, runs first for- 
ward nearly to the diaphragm, then bends upwards to 
the right of the oesophagus, and curves backwards, de- 
creasing in thickness and thus passing imperceptibly 
igth of the head. 
n ?? n 
esophagus and stomach is about 35 cm., and the distance between the 
