430 
SCANDINAVIAN FISHES. 
jaw are also covered with scales, but the intermaxillary 
bones, as well as the lips, are naked. These small 
scales on the head and tins are often the only ones 
that are left after the fish is caught; but the scales of 
the lateral line are at least more firmly attached than 
the scales of the rest of the body itself. As a rule, 
however, the dermal folds in which the scales have 
been set, are so distinct that the number of the scales 
may be ascertained. In the Scandinavian form we have 
found the number of scales in an oblique, transverse 
row at the beginning of the straight part of the lateral 
line, just behind the arch (where the body is deepest), 
to be 13 above and 13 belcuv the lateral line. 
In the form known as Platophrys conspersus the 
length of the head measures 19 — 227 2 % a of the total 
length of the body, 23 — 27 % h of the length from the 
snout to the base of the caudal tin, or 56 — 66 % c of 
the greatest depth of the body. The snout is com- 
paratively blunt, its upper and lower profiles meeting 
almost at a right angle; and the mouth, with the lower 
margin of the under jaw straight, rises, when closed, 
at an angle of about 45 degrees. The length of the 
lower jaw, which is somewhat less on the eye side 
than on the blind side, and in most cases relatively 
less in old specimens than in young, measures 10—12 % 
of the length of the body'*. The chin is furnished 
with a distinct, though small knob; and the anterior 
margin (symphysis) of the lower jaw is straight and 
together with the lower margin forms an obtuse angle. 
The dorsal contour of the snout seems somewhat tumid 
behind the intermaxillary bones, but farther back is 
depressed. This is due to the comparatively advanced 
development of the articular part of the maxillary bones, 
which in other species of the genus, e. g. in Platophrys 
lunatus from the tropical part of the Atlantic, sends 
out a robust, spinous, bony knob in a forward direc- 
tion. In both forms of PI. laterna we have found the 
length of the maxillary bones to be exactly the same 
on the eye side as on the blind side 5 , and to measure, 
in the form known as PI. conspersus , 7—9 % of the 
length of the body 7 , being relatively greater in young 
specimens than in old. Behind (underneath) the max- 
illary bone is slightly extended in breadth, and at the 
posterior (lower) end obliquely truncate and slightly 
concave, more so on the eye side than on the blind 
side. The eyes are of moderate size, measuring 18 to 
20 % of the length of the head, and are, as usual, 
relatively larger in young specimens than in old. Their 
position with regard to each other seems also to vary, 
the variation being to a certain extent individual, but 
chiefly according to age. In the young specimens be- 
fore us they are set almost in a straight line with each 
other, while in the oldest specimen half the upper eye 
is behind the lower, the distance between the latter 
and the tip of the snout being somewhat more than 
its own length. The nasal cavity of the eye side is 
naked, but surrounded with small scales, and is situated 
in front of the eyes, almost exactly in a straight line 
with the narrow interorbital ridge. The position ot 
the nasal cavity of the blind side is similar, but higher, 
its longitudinal diameter, when produced, passing through 
the middle of the upper eye, which is visible through 
the body on this side. The anterior nostril is raised 
on both sides of the body into an obliquely-truncate 
tube, or elongated at the hind margin in a, lobate shape. 
The posterior nostril is smaller, and only slightly raised 
at the margin. The interorbital space, which in other 
species of the genus Platophrys is remarkable for its 
great width and distinct concavity, here consists of an 
extremely narrow 7 ridge, the width of which is only 
about V 3 of the longitudinal diameter of the eye. In 
old specimens the preoperculum is nearly rectangular, 
but rounded at the corner, and with the upper, vertical 
branch 1 / 3 or 1 / i longer than the lower, horizontal 
branch: in young specimens it is more obtuse-angled, 
and the two branches are more equal in size. The 
operculum, suboperculum, and interoperculum, are thin 
and transparent, and together form an arch of almost 
uniform width, until the last of the three grows nar- 
rower in front, below 7 the preoperculum. At the hind 
“ In Scandinavian specimens at most 2 1 1 / .> %, in one of our two Mediterranean specimens 22 1 /., %. In our specimen of PI. arno- 
glossus 24‘7 %. 
h In Scandinavian specimens at most 26 %; in one of our two Mediterranean specimens 27'5 %. In our specimen of Pl. arnoglossus 29'2 %. 
c In the smallest of Collett’s specimens, however, this proportion is 68 %. In the Royal Museum specimen of PI. arnoglossus it is 88’9 y. 
ll In the Royal Museum specimen of PI. arnoglossus the length of the branch of the lower jaw on the blind side is 14'1 % of the 
length of the body. 
e The asymmetry of the mouth and the greater shortness of the head, especially of the postorbital part, and of the pectoral fins are 
the only perceptible differences we have succeeded in discovering between the Chinese Platophrys tapeinosoma and Platophrys conspersus. 
■ r In our specimen of Platophrys arnoglossus the length of the maxillary bones is lO'/o % of that of the body. 
