534 
SCANDINAVIAN FISHES. 
the eye, and its length measures from 9 X /| to a little 
more than 11 % of that of the body or from 47 to 
54 % of that of the head. In front it is a little shorter 
than the upper jaw. The teeth are rather close-set, 
line, and pointed, and form a broad, cardiform row on 
the intermaxillary bones and in the lower jaw, while 
on the head of the vomer they are set in a semicircular 
band. The palatine bones are toothless. There are no 
transverse folds (vela) within the mouth. The four pairs 
of branchial arches are furnished on the inside (in front) 
with a double row of tubercular, but only few gill- 
rakers, 5—7 on the first arch. The cards of pharyngeal 
teeth, the upper ones united into a, roundish patch on 
each side, are composed of densely set, small teeth, and, 
here as in the preceding genus, we find a small patch 
of teeth on the third pair of epibranchial bones. The 
branchiostegal membrane is extended by seven large 
and thick, but only slightly flattened rays. It lies bare, 
is rather large and only slightly, if at all, incised at 
the middle (under the isthmus), where it forms a broad, 
free fold right across to the opposite side. The gill- 
openings are fairly large. The tongue is large and 
fleshy. 
In front of the vent the body is terete, and the 
belly more or less pendent; behind it strongly com- 
pressed laterally and shallower. The hind part of the 
anal aperture is situated at the middle of the length 
of the body, excluding the caudal fin, and the usual 
depth of the body at this point is about 1 G of the 
length to the tip of the tail. The least depth of the 
body, at the base of the caudal fin, is between about 
4 x / 2 (sometimes 4) and 5 x / 2 % of the total length of 
the body or about 22 (sometimes 20) and 28 % of the 
length of the head. The sharper convergence of the 
dorsal and ventral profiles, which proved in the Hake 
to coincide with the beginning of the hindmost sections 
of the dorsal and anal fins, in the Burbot does not ap- 
pear until we reach the beginning of the peduncle of 
the tail, and is sometimes almost imperceptible. The 
lateral line, which is broad and distinct, but only slightly 
depressed and often interrupted, runs from the sides of 
the occiput, in a slight curve, near the back, approaches 
the middle of the sides behind the vent, and advances 
in a straight line to the tip of the tail. All the fins 
have soft, branched, well-separated rays, clothed with 
a firm, thick skin, which is furnished with fine scales. 
The first dorsal fin generally begins at the end of 
the first third of the total length of the body, and 
above the tip of the pectoral fins when laid back. The 
distance between it and the tip of the snout, which 
usually varies between 3 1 x / 2 and 34 x / 2 % of the length 
of the body, may sometimes be as much as 37 x / 2 % 
thereof (cf. above, Ohs.). It contains generally 13, 
seldom 10 or 11 or even 15 or 16 rays, most of which, 
at the middle of the fin, are of equal height, measur- 
ing in most cases about x / 3 or x / 2 of the greatest depth 
of the body, but sometimes even more than 3 / 4 thereof". 
The anterior and posterior rays are variously shortened, 
the latter sometimes missing. The incision which se- 
parates the two dorsal fins, usually goes right down to 
the back, and when the number of rays in the first 
fin is extraordinarily small, this is due to the absence 
of one or two rays at its termination. The length of 
the base of the first dorsal fin is about 8 or 9 % of 
that of the body, though it may sometimes sink to 
about 6 % thereof. The second dorsal fin is of uni- 
form height and generally somewhat higher than the 
first. In most cases it contains about 75 rays, the first 
2, 3, or 4 and the last 4 or 5 diminished in length. 
The distance between the fin and the tip of the snout 
varies between about 40 and 43 % (sometimes 46 %) of 
the length of the body, and the length of its base be- 
tween about 45 and 47 % (sometimes 42 or even 41 %) 
of that of the body. 
The caudal fin is divided from the dorsal and anal 
fins by an incision in the membrane, but in young and 
middle-sized Burbot the notch never extends down to 
the body, and in these specimens no distinct finless 
space (peduncle of the tail), at the dorsal margin at 
least, is ever to be detected. It is first in a Burbot 
of unusual size (age), 9 dm. in length, that we have 
found the peduncle of the tail distinctly marked above 
and below. When the fin is strongly expanded (as in 
the figure), it is perfectly round; but it is generally 
seen in a somewhat folded position, and is then oblong 
and rather pointed, as in the Eel. It contains about 
41 rays, of which 5 or 6 above and below are shortened 
(supporting rays), but not so transformed as in most 
“ One of the Royal Museum specimens from Lake Wetter, with comparatively large head, is further distinguished by the extraordinary 
development of the fins: the height of the first dorsal fin is 9'7 %, the height of the second dorsal fin 9'3 /, the height of the anal fin 6.2 %, 
the length of the pectoral fins 21‘4 %, the length of the ventral fins 18'2 %, and the length of the middle rays of the caudal fin 9'1 % — 
in each case, of the length of the body (483 mm.). 
