POLLACK. 
505 
ness) being about half the depth. In old Pollacks the 
greatest depth of the body is 22 — 25 % of its length, 
in young ones about 19 or 20 %. The head, the length 
of which is about 25 or 26 % of that of the body, is 
of a handsome, cuneiform shape, with depressed fore- 
head, sloping quite evenly to the broad, rounded tip 
of the snout, which is quite thin and low. The sides 
of the head are flat, and almost parallel right out to 
the snout. 
The lower jaw is always distinctly longer than 
the upper, somewhat pointed, and is the extreme tip 
of the wedge formed by the head when the jaws are 
closed. The length of each branch of the lower jaw 
is between about 14 % (in young specimens sometimes 
slightly less) and 1 5 1 / 2 % of the length of the body or 
about 57 — 60 % of that of the head. The upper jaw 
is not protruded when the mouth is opened; and when 
the mouth is closed, the maxillary bones are almost' 
entirely concealed by the labial fold that unites the 
margin of the snout to the suborbital ring. The hind 
extremity of the maxillary bones extends to the per- 
pendicular from the anterior margin of the eye, and 
lies at a distance from the tip of the snout equal to 
about 10 % of the length of the body or 65 — 70 % of 
that of the lower jaw. 
Fine, pointed teeth of uniform size are set in a 
card on the intermaxillary bones and in a simple or 
(in front) double row in the lower jaw and on the 
head of the vomer. The tongue is of an oblong, tri- 
angular shape, rather soft, and with long, free tip. 
The branchiostegal membranes of both sides of the body 
are united inferiorly into a free fold, so broad that the 
margin at the middle extends almost to a line with 
the hind extremity of the lower jaw. 
The eyes are round, and measure 1 / i — 1 / 5 of the 
length of the head, according to the age of the speci- 
men. Their position is such that the line drawn along 
the middle of the body to the tip of the upper jaw 
passes somewhat above the centre of the pupil, which 
lies a little in front of the middle of the head. The 
length of the snout is between about 75 % (sometimes 
70 %) and 78 % of the postorbital length of the head. 
The distance between the eyes is about 65 — 75 % of 
the length of the snout, and in young Pollacks is less, 
in old greater, than the longitudinal diameter of the eyes. 
The nostrils are set in the last third of the length of 
the snout. The hind margin of the anterior nostril on 
each side is raised into a cucullate dermal flap, which 
may be dropped forward like a lid over the small 
aperture. The posterior nostril is larger, but without 
any elevation of the margin. 
The whole head, with the exception of the jaws, 
is covered with scales, though these scales are smaller 
than those of the body. In old and middle-aged Pol- 
lacks the length of the head is about 25 or 26 % of 
that of the body, in very small specimens somewhat 
greater. 
The body is entirely covered with small, thin, and 
imbricated scales, set very densely and firmly attached 
to the skin. These scales are, however, indistinct until 
the skin is partly dry, or the slime has been removed. 
The lateral line is of exactly the same structure as in 
the Whiting, and forms the same upward curve from 
behind, below the second dorsal fin. 
The anal aperture is situated a little behind the 
end of the first third of the length of the body, below 
the last third of the pectoral fins, or somewhat behind the 
perpendicular from the beginning of the first dorsal fin. 
The top of the insertion of the pectoral fins lies 
half-way up the body. These fins are rounded at the 
tip and contain 2 simple and (generally) 17 branched 
rays. The whole base is covered -with scales. The 
ventral fins are still smaller than in the Coalfish, their 
length being about 6V2 0/0 of that of the body, and 
varying to such an extent that in young Pollacks it is 
about half, in old considerably less than half, of the 
distance between their insertion and the beginning of 
the anal fin, a distance which increases with age from 
about 13 or 12 % to nearly 16 % of the length of the 
body. They are set somewhat in front of the pectoral 
fins, and are made up, as usual, of 6 rays, the first 
two simple or the second indistinctly cleft, the others 
branched at the tip. None of these rays has a long, 
free tip, and the third ray is the longest. 
The three dorsal fins are of normal structure, 
rather thick, and covered with scales. The first begins 
at a distance from the tip of the snout measuring 33 
or 34 % of the length of the body, and the length of 
its base is about 9 — 11 % of the same length. The 
first two or three rays are simple, but soft at the tip, 
and the third or fourth ray is the longest, its length 
in young Pollacks being usually rather more, in old 
rather less, than the postorbital length of the head. 
The fin-membrane is entirely covered with rather fine 
scales out to the margin. The second dorsal fin be- 
gins at a distance from the tip of the snout equal to 
G4 
Scandinavian Fishes . 
