576 
SCANDINAVIAN FISHES. 
lateral line contains about 125 scales; and the oblique 
dermal folds on the sides of the body number about 
130, being thus fewer than in the Sand-Eel. It is also 
easy to see, on comparing specimens of equal size, that 
the scales of the Sand-Launce are larger. The anal 
aperture lies nearer the middle of the body, the distance 
between it and the tip of the lower jaw measuring, 
according to Kroyer, about 53 — 56 % of the length of 
the body to the end of the outermost caudal rays. We 
have found the distance between it and the tip of the 
snout, in specimens from 97 to 130 mm. long, to rise 
from 5 6 3 / 4 to 587 2 % of the length of the body to 
the end of the middle caudal rays'*. 
The dorsal fin generally begins somewhat further 
forward than in the Sand-Eel, usually in front of the 
end of the first fourth of the length of the body, but 
sometimes behind it. On the other hand, its extent 
is apparently always somewhat greater, sometimes as 
much as 2 / 3 of the length of the body. Consequently, 
the distance between it and the tip of the snout, accord- 
ing to our measurements, never exceeds 40 % of the 
length of its base 6 . As a rule too, its length increases 
even relatively with age, the length of the head in 
specimens about 9 cm. long measuring 28' 7 % of the 
length of the base of the dorsal fin, in specimens be- 
tween 13 and 20 cm. long only 26*7 % thereof 0 . The 
anal fin generally begins somewhat further forward and 
in most cases is of somewhat greater extent than in 
the Sand-Eel; but in both species the length of its 
base varies between 48 and 43 % (in the Sand-Launce 
exceptionally 41 '3 %). In the caudal fin we find no 
characteristic peculiarity worthy of mention, the least 
depth of the tail in this species, too, being generally 
somewhat more'' than half the length of the middle 
rays of the caudal fin. 
In the Sand-Launce the pectoral fins always extend 
distinctly (for V 4 — 1 / 8 of their otvn length) behind the 
perpendicular from the beginning of the dorsal fin. 
Their length is at least somewhat more than 9 % (ac- 
cording to our measurements 9'1 — 10'3 %) of that of 
the body, than 37 % (43 — 37'2 %) of the distance be- 
tween the dorsal fin and the tip of the snout, or than 
90 % (1 13*6 — 90' 1 %) of the postorbital length of the 
head. They are also always longer than the lower jaw, 
the length of which we have found to vary between 
80 and 95 % of that of these fins. 
The coloration is the same as that of the Sand- 
Eel, but is often more bluish, olive-green with steel- 
blue lustre, on the back. The young specimens in par- 
ticular are finely punctated with round, dark brown 
spots, one row above the lateral line, one row below 
it, and a third row along the base of the dorsal fin 
composed of somewhat larger pigmental spots. This 
marking is, however, by no means peculiar to the Sand- 
Launce. The upper part of the silvery white iris is in 
most cases more shaded with black than is usually the 
case in the Sand-Eel, where the whole iris is generally 
silvery. In tins species too, the lower part of the sides 
has a silvery lustre, but the belly is of a duller white. 
The youngest specimens have a row of dark brown, 
pigmental spots along each side of the base of the anal 
fin. The snout is without the black spot on the sides, 
or possesses merely a trace of this spot in the form of 
scattered pigmental spots, larger and denser than on 
the rest of the snout. The tip of the lower jaw is also 
destitute of the black colour which we find there in 
most Sand-Eels, at least in old specimens. The caudal 
fin is darkened at the base above and below by brown 
pigment between the rays. The peritoneum is silvery 
white as in the Sand-Eel, but more densely punctated 
with small, round dots of black pigment, sometimes so 
dense that the preponderating colour of the membrane 
becomes coal-black. 
In order to ascertain the natural relations between 
these three species of European Sand-Eels, we shall now 
notice some points in the manner in which the most 
a In specimens of the Sand-Eel between 135 and 289 mm. 
to advance with fair regularity. 
b From 40 to 36 % in the Sand-Launce; 
c In Sand-Eels between 11 and 29 cm. 
the percentage was 
d Sometimes 
significant characteristics appear in these species. In 
general Ammodytes lanceolatus has a longer head, measur- 
ing more than Vs °f the length of the body; but 
long, this proportion rises from 59'2 to 60'2 %, the increase thus seeming 
33 to 30’6 /. In a Sand-Launce 56 mm. long, however, 
from 45 to 44 % in the Sand-Eel. 
long this proportion sinks from 
32-1. 
perceptibly less, however, according to Kroyer. 
