608 
SCANDINAVIAN FISHES. 
perceptibly more than half (at least 55 %) of the distance 
between the anal fin and the latter. 
The changes caused by age in the coloration of 
Lycodes are extraordinarily great. All the fry — with 
the exception of one species — are adorned with a hand- 
some, regular marking (see for example tigs. 148 and 
150) of selliform, dark-margined spots across the dorsal 
lin and the back. On the hindmost part of the tail 
these spots are generally prolonged downwards, forming 
transverse bands across the dorsal fin, the body, and 
the anal fin. The spaces between the spots grow lighter 
and lighter, being sometimes milk-white on the dorsal 
fin and the back, and the same light colour sometimes 
appears in the form of an ocellated spot within one or 
another of the selliform spots. With age, however, 
these selliform spots coalesce below, and the boundary 
between them and the coloration of the rest of the 
body is effaced, being sometimes replaced by a net- 
work of darker colour, starting from the original dark- 
coloured margin of the spots. These changes of colo- 
ration are also common to other kindred genera within 
the family, and strongly remind us of the distribution 
of the spots in the Eelpouts, in all its irregularity. 
The dentition of the palatine bones and of the head 
of the vomer in Lycodes — a character which is wanting 
in the Eelpouts — is here counterbalanced by a nega- 
tive character, the absence of transverse palatal folds 
behind the rows of teeth in the jaws. The nostrils are 
simple and tubular in this genus also, but the snout 
is more elongated and of a looser structure, this being 
due to the still greater development of the cavities be- 
longing to the cephalic system of the lateral line. The 
extension of this system over the body is singular 
enough. No less than three lateral lines may appear 
on each side of the body — but, as far as we know, 
no more than two in the same individual. These lines 
are generally wanting in young specimens and are again 
effaced in old. In most cases two lateral lines start 
from each temporal region, one — corresponding to the 
ordinary mediolateral line ■ — in a slight curve down- 
wards to the middle of the side, or even down to the 
anal region and then along the base of the anal fin, 
the other — a dorsal line — usually with larger but 
more scattered pores and seldom extending farther than 
to a line with the vent or a little behind it. Sometimes 
again a ventral branch starts from the anterior part of 
the mediolateral line, its structure being' the same as 
that of the latter. Lutken, who was the first" to draw 
attention to all these differences, based upon them a 
system of determining the species within the genus; 
but Gunther has pointed out- 6 the systematic difficulties 
involved in a strict adherence to characters derived 
from this relation, characters which at different ages 
and in different individuals show variations, the cause 
of which is as yet unknown, and which also in many 
cases defy observation. Gunther passes the same judg- 
ment upon the characters which have been drawn from 
the extent of the scales in these fishes. 
Ever since Richardson described his Lycodes rnu- 
cosus from Northumberland Sound", we have known 
that scales may be wanting within this genus in indi- 
viduals up to a length of 28 cm. In 1874 <z Sleeker 
founded the genus Lycodalepis to emphasise this cha- 
racter, which, according to Bean", may be persistent- 
in the species just mentioned even at a length of 43 
cm. However, to the best of our judgment and with 
the knowledge we now possess of the changes of growth 
and sexual differences within the genus, this species 
can scarcely be distinguished, except perhaps as a local 
variety, from Lycodes Turneri, the form described by 
Bean 7 and Turner 5 ' from Alaska, or from the form 
brought home by the Vega Expedition 6 from the en- 
trance of Chatanga Bay (Siberia, E. of Cape Tschelju- 
skin). The latter form is in all probability identical 
with the form subsequently described by Lutken' under 
Collett’s name of Lycodes Lutkenii, which Gunther 
a Vid. Meddel. Naturh. For. Kbhvn 1879 — 80, p. 329. Kroyer, however, had already remarked a dorsal and a mediolateral line in 
his Lycodes perspicillum (Naturh. Tidskr. Kbhvn, ser. Ill, vol. I, (1862), p. 292). 
b Deep Sea Fish., Cliall. Exped., p. 79. 
c The Last of the Arctic Voyages, vol. II, p. 362. 
d Vers]., Med. Akad. Wet. Amster., 2 R., 8 Del, p. 369. 
c Bull. U. S. Nat. Mus., No. 15, p. 113. 
f Proc. U. S. Nat. Mus., vol. I, p. 463. 
■' Contrib. Nat. Hist. Alaska , Arct. Ser. Publ. Sign. Serv. U. S. Army, No. II, p. 93, PI. 4. 
h Gr. Intern. Fisher. Exhib. London 1883, Swed. Catal., p. 176. 
' Kara-Havets Fiske , Dijmphna-Togtets Zool.-bot. Udb., p. 14, Tab. XVI. In the largest of these specimens Lutken remarked a 
considerably greater number (13 — 15) of palatine teeth than in Lycodes mucosus (7, both according to Richardson’s figure and in the speci- 
men from Chatanga Bay). But the great resemblance in other respects between these nominal species forces us to the conclusion that this 
difference is individual and may depend on circumstances of age or sex, unless indeed it belongs to a local variety. 
