614 
SCANDINAVIAN FISHES. 
with certainty; and a more trustworthy expression of 
the character may always be found in the proportion 
between the length of the head and that of the tail. 
In its adult state this species is also better equipped 
with scales, though the variations seem to be quite as 
great as in the preceding species. On the grounds 
given above, and as constant characters of form are an 
indispensable condition of systematic clearness, we com- 
bine under one specific name the two forms, Lycodes 
Vahlii and L. Esmarkii, which have recently been 
distinguished on account of the difference in the den- 
tition as stated by Lutken. 
In form the body resembles that of the Eelpout, 
with the characteristics common to all the Lycodes. 
The head, which with its flat under surface presents in 
the adult fishes the form of a cone longitudinally bi- 
sected and somewhat obtuse at the tip, generally mea- 
sures in young specimens and in the females rather less, 
in the males rather more, than 22 % of the length of 
the body, varying in this manner between 1 8 1 / 2 and 
23 V 2 % thereof. The only noteworthy irregularity in its 
conical shape is formed by the more or less tumid 
cheeks (the masticatory muscles). In young specimens 
the large muciferous cavities along the upper and lower 
jaAvs are especially distinct, generally in the form of 
holloAv depressions; but in the older specimens these 
depressions disappear. On each side of the snout, at 
about the middle of its depth and nearer to the tip of 
the snout than to the eye, lies a single tubular nostril. 
The eye is oblong and not very sharply marked off from 
the surrounding skin, Avhich coalesces Avith the trans- 
parent cornea. The length of the eye varies between 
about 7 % (in the fry) and 2 % of that of the body 
(the latter proportion in the most developed individuals). 
Its position is such that in the fry the postorbital length 
of the head measures about 44 % of its entire length, 
in adult specimens about 55 % thereof, with all the 
variations lying between these two percentages. The 
sides of the occiput end each in an obtusely pointed 
and triangular, opercular flap, Avhich in old specimens 
lies a little above and behind the upper end of the root 
of the pectoral fin and sometimes measures at the upper, 
free margin nearly half the length of the remainder of 
the postorbital part. The loAver angle of the gill-opening 
lies on a level Avith the loAver angle of the pectoral fin 
and in a line Avith the preoperculum, the breadth of 
" According to Goode and Bean (1. c.) the length of the. lowi 
in a male 632 mm. long 1 Of ,, % thereof. 
the isthmus between the two gill-openings being about 
equal to the length of the nose between the nostril and 
the eye. The length of the loAver jatv varies, according 
to our measurements, between about 10 and 11 1 / 2 % of 
that of the body", and is generally someAvhat less than 
in the preceding species. The cleft of the mouth is 
horizontal; it extends in young specimens hardly any 
distance, if at all, behind the perpendicular from the 
anterior margin of the eye, but in old specimens di- 
stinctly beyond this line. In old specimens the hind 
extremity of the maxillary bones lies in a line Avith the 
posterior part of the eye, the distance betAveen the tip 
of the snout and this extremity measuring in the fry 
about 7 % of the length of the body, in old specimens 
up to at least 1 1 3 / 8 % thereof. This elongation of the 
labial parts involves a more advanced development of the 
teeth. The teeth in the jaAvs and on the palate are strong, 
almost cylindrical, more less curved, and rather scattered. 
They are largest in the anterior part of the intermaxil- 
lary bones and of the loAver jaw, and are here set in 
old specimens in three or even four toavs, in young in 
only two, the number of the toavs decreasing behind 
until at last there is onty one roAv or sometimes, in 
the loAver jaw, two. The foremost teeth in the jaws 
are directed straight forward. The i’oavs of intermaxil- 
lary teeth do not extend further back, even in old spe- 
cimens, than to about a line Avith the middle of the 
snout, Avhile in the lower jaw the roAvs extend beyond 
the corners of the mouth. On the other hand, the fore- 
most intermaxillary teeth are set under the projecting 
part of the snout, in front of the tip of the loAver jaw. 
On the head of the vomer Ave find from 5 to 8 teeth 
of more conical form, arranged transversely in a trian- 
gular group. On the palatine bones, according to Col- 
lett, Lycodes Esmarkii ahvays has 9 — 11 teeth in a 
single or irregularly double toav; Avhile in L. Vahlii, 
according to Lutken, these bones are set Avith 11 — 14 
teeth in the females and Avith someAvhat feAver than 20 
in the males, ahvays in a double roAv. Such is the 
tenour of the proposed specific distinction, or in other 
Avords: “The toav of palatine teeth is never longer than 
the intermaxillary toav, but in most cases (especially in 
adult specimens) considerably shorter, sometimes scarcely 
half as long” (Coll., of Lycodes Esmarkii ), and: “The 
roAv of palatine teeth is generally longer than the in- 
termaxillary roAv, at least only slightly, if at all, shorter 
er jaw in a female 540 mm. long was 9 1 2 % of ihat of Hie body and 
