940 
SCANDINAVIAN FISHES. 
and only a little shorter than the second, which is the 
longest in the fin and branched like the remaining 9 or 
10 rays, which rapidly and regularly decrease in length 
towards the bottom of the fin. In the ventral fins the 
first (outermost) two rays are simple, the first ray 
being, however, extremely small (rudimentary). The 
second simple ray is but slightly shorter than the third 
ray, which is branched and only a little • shorter than 
the next, the length of which is equal to, or only a little 
less than, that of the third and fourth branched rays. 
'Fhe other branched rays (5th — 7th) gradually decrease 
in length. Along the inner margin of the last ray runs 
a thickened growth of fin-membrane, with the appear- 
ance of a defectively developed ray. The under sur- 
face of the ventral fins seems, like the sides of the 
caudal fin, to be clothed with elongated scales. 
The whole body is densely covered with scales, 
which extend forward on the head over the whole inter- 
orbital space, but are deciduous, the specimens taken 
being generally scaleless, or with only a part of the 
lateral line left. The scales (fig. 234, a) are thin, trans- 
parent, and flexible, rather large and of equal size, 
rounded or of a broad elliptical shape, set in the trans- 
verse direction of the body (with the vertical diameter 
greater than the horizontal); their nucleus is central; 
they are furnished with dense concentric striae and a 
few (4 — 6) grooves radiating forwards and backwards. 
These grooves, between which the concentric striae (thick- 
ened and elevated lines) are sharply curved, render the 
anterior margin of the scale sinuate, the posterior (free) 
margin irregularly erose. In the nucleus of the scale and 
the immediate neighbourhood of the nucleus, as ’well as 
in an angular patch coinciding with the margin of the 
dermal follicle, the concentric striae are joined at right 
angles by transverse striae, and in the hind (free) part of 
the scale they are irregularly broken up here and there, 
crossing each other in a network. The scales of the 
lateral line (fig. 234, b) have a short, pear-shaped duct 
at the centre of their outer surface, and are indented 
in a heart-shaped form, but deeply, at the hind (free) 
margin, by a narrow sinus, which widens, however, in 
front (towards the centre of the scale) in a stilliform 
manner. Pointed and elongated scales appear not only, 
as we have mentioned above, on the sides of the caudal 
fin and the under surface of the ventrals, but also in a 
row along the base of the dorsal fin, where they are 
more or less deformed (fig. 234, c), as if they were 
only half-scales, with laterally set nucleus and an in- 
creased number of grooves (about 9) obliquely radiating 
towards the anterior margin. 
According to Costa’s figure the coloration of the 
whole dorsal side (including the upper part of the head) 
and the lower posterior part of the tail is brownish red, 
of the opercular apparatus shifting green and black, of 
the ventral side dark brown, of the sides of the head 
silvery. The few scales still adhering to the specimen 
kindly lent us from Christiania Museum suggest that the 
silvery lustre extended throughout the sides of the body; 
but where the scales are wanting, the skin of the sides 
(in spirit-preserved specimens) is also brownish red. 
Back from the occiput, sometimes to a line with the 
adipose fin (according to Storm), there run on each side 
one or two rows of orange spots, caused, according to 
Collett, by the fact that each scale in the two rows 
next above the lateral line bears a similar spot at its 
tip. These spots are visible, however, though faint, in 
the skin, after the scales have dropped off. Costa 
figures some of them, along the base of the dorsal fin, 
as luminous spots. 
The true luminous spots are here (in spirit-pre- 
served specimens) of a greenish lustre. The largest on 
each side lies on the lower part of the hind preoper- 
cular margin. The three spots belonging to each hyoid 
arch we have already mentioned. The remaining spots 
are arranged, in the specimen now before us, as follows. 
Behind the shoulder-girdle, down to the isthmus, where 
the lowest spot lies just behind the posterior extremity 
of the lower jaw, runs a row of spots, the third from 
above being situated at the lower angle of the pectoral 
fin. In front of the ventral fins (on the preabdominal 
region) we find, on each side of the median line of the 
belly, a row of 3 luminous spots, and up the side of 
the body this row is continued obliquely backwards by 
a spot just before the outer angle of the insertion of 
the ventral fin and another set halfway up towards the 
lateral line. Behind the ventral fins (on the postabdo- 
minal region) there runs, on each side of the median 
line of the belly, from the hind (inner) angle of the 
insertion of the ventral fin to a line with the anal aper- 
ture, a row of 5 spots, and this row is continued up 
the side of the body by 3 spots, the uppermost of which 
is set on the lower portion of a scale in the lateral 
line. Along each side of the base of the anal fin is a 
row of 9 spots, and on the lower part of each scale in 
the lateral line above the end of this row there lie 2 
spots. After a break measuring twice the distance be- 
