274 
SCANDINAVIAN FISHES. 
point, strongly depressed and thin, resembling a labial 
fold which covers the upper jaw, and underneath which 
the latter may be drawn in. The margin of the upper 
jaw, which projects beyond the lower, is formed by the 
fairly firmly united and somewhat arcuate intermaxillary 
bones, which form a kind of beak. These bones are 
furnished with long nasal processes, which slide along 
the facial bones, and contribute to the marked pro- 
trusion of the upper jaw, when the mouth is opened. 
The latter then acquires a tubular appearance, and is 
turned obliquely downwards, as we have endeavoured 
to show iu the outline drawing in Plate XIV. The 
maxillary bones are very small, situated behind the 
intermaxillaries and hidden by the labiate skin of the 
snout, their lower end being visible only when the 
mouth is opened and protruded. Both jaws are fur- 
nished with fairly fleshy lips and very small, cardiform 
teeth. There are no teeth on the palate or on the 
tongue, which is small, cartilaginous and rounded to a 
point, with a small, soft rim round the free tip. A 
small, transverse, membranous fold appears on the pa- 
late, but there is no corresponding fold below it. The 
eyes are set high and close to each other, but are turned 
in a lateral direction, the eyeballs, which project above 
the level of the forehead, being superiorly depressed. 
The pupil is kidney-shaped, there being a lobate process 
in the upper- margin of the iris. The nostrils are very 
small and are set quite close to the eyes; the anterior 
opening is somewhat tubular, the posterior almost in- 
visible. At the lower corner of the preoperculum we 
find a projecting hand-shaped process, which is gener- 
ally furnished at the end with 3 pointed, subulate spines, 
directed upwards and backwards, and inferiorly with a 
spine pointing forward, which lies, however, along the 
base of the process, hidden by the skin, and is there- 
fore easily overlooked. The fish is not unskilled in the 
use of these weapons. When an attempt is made to lift 
it, it expands the gill-covers, like the Bullheads, the 
spinous processes being thus erected. The operculum 
is small and very thin, with soft, cartilaginous margin. 
The gill-openings are small round holes on each side 
of the occiput, with a thin, loose membrane at the 
margin, which closes them like a valve. The remainder 
of the opercular margin is united to the body by the 
skin, 'fhe branchiostegal membrane is furnished with 
6 rays, all fine and soft, with hairlike tips, the upper- 
most three being especially long and bent round the I 
opercular margin. The branchial cavity is narrow, with 
small gills and narrow openings between the arches; 
the anterior margins of the latter are furnished with 
two rows of small, verrucose, osseous protuberances (gill- 
rakers). Idle upper pharyngeals are loosely united into 
two rounded almond-shaped plates, entirely rough with 
line, cardiform teeth. The lower pharyngeals are of the 
ordinary oblong shape, and are armed in the same way. 
The skin of the body is throughout thin and smooth, 
without any trace of scales, and covered with an abun- 
dant mucous secretion. At several spots it is so loosely 
attached to the body that it may be raised into folds. 
The lateral line is scarcely visible, but runs in the form 
of a somewhat raised seam along the middle of the 
sides, its course being fairly straight, though somewhat 
winding. It advances out to the hind margin of the 
caudal fin, lying between the third and fourth rays 
thereof. Straight across the occiput there runs a- con- 
necting-duct between the two lateral lines. On the 
hind part of the body, from the middle of the second 
dorsal fin, we generally find transverse branches of the 
lateral line, alternately in an upward and a downward 
direction, one running straight up, and the next, which 
is shorter, obliquely downwards. One or two such 
branches rise from the lateral line on each side, meet- 
ing at the dorsal edge, just in front of the caudal fin, 
and thus forming connecting ducts. The vent is situ- 
ated in front of the middle of the body, almost verti- 
cally below the second ray of the second dorsal fin. 
Two dorsal fins rise from the depression which runs 
along the dorsal edge. The anterior is triangular, and 
begins above the upper angle of the base of the pec- 
toral fin, at a distance from the middle of the point of 
the intermaxillary bones, when drawn back, which mea- 
sures from 25 to 28 % of the length of the body. It 
contains only four, simple, soft-tipped rays, which are 
followed by the fin-membrane out to the very tip. The 
first ray is the longest, the others gradually diminish- 
ing in length. The second dorsal fin, which begins near 
the end of the first, generally contains eight “ simple 
rays, all of which are articulated, and at the end one 
ray branched down to the base, and with the branches 
also divided at the tip. The length of its base de- 
creases with age from about 26 to 23 % of the length 
of the body. The anal fin is of the same shape and 
structure as the second dorsal, but begins a little farther 
back than the latter, the distance between it and the 
Sometimes only 7 . 
