LYCODO IDS. 
had unhesitatingly referred to the old Rein hard t.ian 
species Lycodes reticulatus. This form, which belongs 
to Kara Sea, is furnished when 225 mm. long, accord- 
ing to Luticen, with scales over the whole tail and the 
greater part of the back behind the beginning of the 
dorsal tin; but the above-mentioned specimen from 
Chatanga Bay, which we proposed in 1882 to refer to 
Lycodes , mucosus, is entirely scaleless at a. length of 
24(1 mm. The individual variations in this respect 
seem to be so great that we must abandon the attempt 
to base the determination of the species upon the pre- 
sence or absence of scales. No more reliance can be 
placed on the proposed determination — here as in the 
Gobies — based on the greater or less extent of the 
scaly covering in a forward direction, over the trunk 
and head, in those forms which are furnished with 
scales at an early age and retain them at all sub- 
sequent ages. 
The differentiation of the species within this genus 
from each other is a more advanced development of the 
specific difference which seems to be present, but can 
scarcely be regarded as fixed, within the preceding 
genus. A trace of the most essential difference between 
the European and the American Eelpout may be found, 
as we have seen above, in the two forms that can be 
distinguished with tolerable ease among the European 
Eelpouts, and may be reduced to a greater or less 
elongation of the caudal part of the body, in combina- 
tion with a greater or less number of vertebra?. So 
also within the genus Lycodes we can distinguish be- 
tween two main groups of forms, the first with com- 
paratively shorter body, like that of the Eelpout or 
even deeper than it, the second with exceedingly elong- 
ated, more Anguilliform body. Within these groups 
the most general specific difference lies in the same 
relation, conjoined with the varying size of the head, 
originally a distinction of sex and age, for the relative 
609 
length of the head generally increases with age and is 
always greater in the males than in the females. 
The genus is composed exclusively of deep-sea 
fishes, most of them living at depths of from 300 to 
500 fathoms or more, and at least one species taken 
in 1,333 fathoms of water. During youth, however, 
they are met with nearer land and in shallower water, 
sometimes at a depth of only 50 or 30 fathoms. For 
the scientific elucidation of these forms we have prin- 
cipally to thank Collett and Lutken. To the gene- 
rality of fishermen the genus is unknown, and it has 
no popular name; Lilljeborg has proposed the Swedish 
names of dlbrosmar or dllubbar (Eel-Torsks). 
The species that belong to the Scandinavian fauna 
may be distinguished in the following manner: 
A: Depth of the body at the beginning of 
the anal fin more than 8 % of its length. 
Branchiostegal rays 6. 
a: Body plain, without spots Lycodes frigidus. 
b: Coloration light with dark-edged, sel- 
liform spots in the fry, in adult spe- 
cimens dark with light transverse 
spots or light with dark transverse 
spots. 
a: Length of the head more than 
39 % of that of the tail from the 
beginning of the anal fin to the 
tip of the last fin-rays Lycode, s reticulatus. 
fj : Length of the head less than 39 
% of that of the tail from the 
beginning of the anal fin to the 
tip of the last fin-rays Lycodes Valdii. 
B: Depth of the body at the beginning of 
.the anal fin less than 8 % of its length. 
Branchiostegal rays 5. 
a: Length of the head at least about 
*/ 4 (more than 23 %) of that of the 
tail from the beginning of the anal 
fin to the tip of the last fin-rays... Lycodes Sarsii. 
fj: Length of the head at most about 
'/- (scarcely more than 20%) of that 
of the tail from the beginning of the 
anal fin to the tip of the last fin-rays Lycodes murcena. 
