380 
SCANDINAVIAN FISHES. 
in front of the first muciferous cavity of the dorsal 
margin; and the anterior nostril lies obliquely above 
the posterior, which has the form of a slit, but is so 
obliquely set that it is almost parallel to the dorsal 
margin of the head. The eyes are fairly large. The 
longitudinal diameter of the upper orbit measures nearly 
half the length of the cranium from the head of the 
vomer to the occipital foramen; and the longitudinal 
diameter of the eyes themselves (the upper eye is some- 
what larger than the lower), measured within the der- 
mal folds that serve as eyelids, is about 1 /. i of the total 
length of the head. Half or a third of the upper eye 
lies behind the perpendicular from the hind margin of 
the lower. The mouth is small, the length of the 
maxillary bones varying between about 3 and 3 V 2 %“ 
of that of the body, and the length of the lower jaw 
between about 5 and 6 % b thereof. The transverse 
palatal folds are well-developed, though not large, both 
in the upper jaw and the lower. The lower jaw is 
furnished with a well-developed chin protuberance under 
the symphysis. The lips are fleshy, but not tumid, 
'fhe jaw-teeth, which are pointed in young specimens', 
subsequently become chisel-shaped. The gill-rakers are 
well-developed but scattered, and set in a single row, 
containing about 8 on the first branchial arch. On the 
lower pharyngeals, which are narrow and long (like 
branchial arches), these spines are exchanged for a double 
row of conical, obtusely pointed teeth. The roof of the 
palate, as usual, is truncate posteriorly, with a deep 
pharyngeal cavity behind it, into which is fitted the 
upper pharyngeal apparatus, consisting of three pairs 
of pharyngeals directed outwards and backwards, each 
with a row of six or seven conical teeth. The tongue 
is small and narrow, but the hyoid surface (copular 
part) is continuous and fleshy, widening into a triangle 
behind. The pseudobranchias are set just behind the 
upper articulation of the hyomandibular bones, at the 
extreme front of the pharyngeal cavity mentioned above. 
The preoperculum of the eye side is more obtuse-angled 
than that of the blind side, the latter being also fur- 
nished with broader margin and much larger muciferous 
cavities. The operculum forms an almost equilateral 
triangle, as in most of the Flatfishes, with the hind 
upper corner rounded and the lower posterior margin 
incised. The suboperculum is as usual elongated back- 
wards and upwards to a point, which fills this incision, 
the suboperculum thus forming the greater part of the 
hind margin of the gill-cover, up to the obtuse flap of 
this margin. The interoperculum is attenuated anteriorly. 
The branchiostegal membranes are as usual free, but 
interiorly united to each other in a, broad transverse 
fold, where the tips of the first two branchiostegal rays 
touch. In ordinary cases this transverse fold covers 
the point of the clavicular bones; but when the gill- 
cavity is strongly expanded, the fold is drawn so tight, 
into the angle of the urohyoid bone, that the point of the 
clavicular bones is externally visible as a forward process'*. 
The dorsal fin begins above the middle or the front 
of the upper eye, exactly at the dorsal margin or with 
the first ray alone slightly drawn over towards the blind 
side, and extends back to a point the distance between 
which and the caudal fin is about half the diameter of 
the eye. fhe dorsal fin is evenly rounded, the longest 
rays being situated at the middle of its length, and 
their length being about equal to the vertical height 
of the preoperculum. The anal fin, which begins be- 
hind the anal spine, a little behind the perpendicular 
from the insertion of the pectoral fins and below the 
16th, 17th, or 18th ray of the dorsal fin, at a distance 
from the tip of the snout that measures about 19 — 24 
% of the length of the body, is of the same shape and 
height and ends in the same manner as the dorsal fin. 
All the rays in the dorsal and anal fins are simple', 
articulated, and undivided. The pectoral and ventral 
fins are pointed, seem generally to be longer in the 
males than in the females*, and are always somewhat 
“ On the blind side, according to our measurements, at least 3‘3 % and at most 3'7 %, on the eye side at least 2'9 °/ and at most 3’4 %. 
b On the blind side, according to our measurements, at least 5'3 % and at most 5'9 %, on the eye side at least 4'7 % and at most 5’6 %. 
On the blind side we have found the length of the lower jaw (in specimens between 378 and 516 mm. in length) to vary between 81 1 /,, and 
84'/->% of the least depth of the tail; on the eye side between 72 and 83 % thereof. According to Kroyek’s measurements, however, the last 
proportion may be as low as 66'7 %. 
c “Conical and separated:” Goode and Bean, 1. c. 
d The urohyoid bone is united by a long ligament to the hyoid bone, but is closely joined to the clavicular bones. 
e “Sometimes,” says Gottsche, however, “the last rays of the dorsal tin are branched.” 
7 In three males, between 378 and 516 mm. long, the minimum length of the pectoral fins was 9'2 % and the maximum 12'6 % of 
the length of the body, while in the case of the ventral fins these proportions were respectively 5'5 and 1'2%. In three females, between 
418 and 470 mm. long, the minimum length of the former fins was 7'6 % and the maximum 8’8 % of the length of the body, while in the 
case of the ventral fins these proportions were respectively 5 and 5'1 %. 
