944 
SCANDINAVIAN FISHES. 
its hind margin is without the deep, narrow incision, 
though according to Kroyer’s figure of this species the 
incision is sometimes present in the lateral scales. On 
the head the scales advance over at least the greater 
part of the interorbital space, and large scales, as we 
have mentioned above, cover the whole opercular appa- 
ratus. On the posterior, expanded part of each maxil- 
lary lies an obliquely linguiform scale (triangular with 
rounded corners), entirely covering this part; and the 
bases both of the pectoral and ventral fins are covered 
with several scales. 
The true luminous spots are comparatively small 
and have a yellowish lustre. The hind margin of the 
preoperculum, at the limit between the operculum and 
suboperculum, is furnished with a luminous spot, and 
exactly below this point, at the upper anterior angle 
of the interoperculum lies another. Through each branch 
of the lower jaw there shine three spots. On each of 
the clavicles there are two spots. One spot is situated 
at the lower angle of the insertion of each pectoral fin. 
From the isthmus to the ventral fins there runs on each 
side of the ventral margin a row of five spots. Between 
the insertion of the ventral fins and the beginning of 
the anal fin this row is continued by four spots, and 
along each side of the base of the anal fin by seven 
more. Between the anal and caudal fins, which part is 
damaged in our specimen, both Krgyer and Collett 
found six spots in a row on each side of the ventral 
margin. An upper row on each side of the body, in 
the abdominal region and on a level with the spot at 
the base of the pectoral fin, contains three spots, all 
belonging to the row of scales next below the lateral 
line, the foremost of them situated at the end of the 
preabdominal region, the other two in the posterior part 
of the postabdominal region. On each side of the tail 
there also runs a row of three spots, but this lies higher 
up, each spot being situated on the lower part of a 
scale in the lateral line, the first spot above the space 
between the first pair in the row along the base of the 
anal fin, the second in a similar relation to the last 
pair in the said row, and the third at the extreme end 
of the peduncle of the tail. At the dorsal margin of 
the tail, just in front of the upper supporting rays of 
° See Die Augenahnliche Organe der Fische, p. 52, and Len 
or “stern-chasers” of Scopelus-. 
This species is similar to Myctophum gJaciale in most respe 
gards the tail, the body thus being relatively deeper, and the head la 
in the caudal part of the lateral line are wanting. 
c See Day, 1. c. 
the caudal fin, traces appear in our specimen of a large, 
composite, luminous spot, Leydig’s Perlfleck or Perl- 
grauer Fleck". At the middle of the interorbital space 
lies a spot (an epiphyseal body or a parietal organ?), 
which in Scopelus Bissoi b , a nearly related Mediterranean 
form, has even more of the appearance of a luminous spot. 
The coloration of the body, according to Ivrgyer, 
is of a brownish green or an olive hue on the back, of 
a brassy lustre on the sides (with a. bright golden lustre, 
according to Gray c ), of a darker olive-green under the 
belly. The cavity of the mouth and the branchial ca- 
vity, as well as the peritoneum, are black. 
The internal organs have been described by Krgyeil 
The liver is short but thick, with three lobes, the left 
one being the largest; the gall-bladder is small. The 
oesophagus is short but wide, the stomach small but 
somewhat saccate. Behind the pylorus hang 8 rather 
large ciecal appendages. The intestine is straight but 
rather wide. The saccate air-bladder extends about half- 
way along the abdominal cavity, and is connected by its 
pneumatic duct with the oesophagus. The generative 
organs lie as usual in the posterior half of the abdo- 
minal cavity, and have complete efferent ducts. 
The Arctic Scopelus has long been known in the 
Scandinavian fauna, but is still rarer than the preceding 
species. In 1774 a specimen was taken by Strom at 
Sondmor; but since that occasion only 3 specimens have 
been met with, to the best of our knowledge, on the 
coast of Norway, and not a single specimen has ever 
been found on the Swedish or the Danish coast. One 
of the said 3 specimens — the very specimen which has 
been kindly lent us from the Museum of Bergen — was 
taken by Governor Christie about 1830, probably in 
Hardanger Fjord; the second was sent from Haswig, 
near Hammerfest, to Christiania Museum by Mr. Bull; 
and the third 'was found by the Norwegian North At- 
lantic Expedition in June, 1876, floating at the surface 
on the fishing-bank of Storegg off Aalesund. The spe- 
cies would seem to be commoner on the coast of Green- 
land, from which locality the Museum of Copenhagen 
has received several specimens, both from the northern 
and the more southern colonies, and in the Arctic Ocean, 
where the Norwegian North Atlantic Expedition took it 
eneeld, Deep Sea Fish., Challeng. Exped., p. 302, The dorsal organs 
:s; but the form of the body is still more shortened, especially as re- 
•ger, while the above-mentioned luminous spots belonging to the scales 
