HERRING. 
955 
of a . The least depth of the body (of the tail) mea- 
sures on an average 67 3 — 67 2 0// ° h °f the said length. 
According to the method of measuring the length of 
the body employed above, in the case of the Gwyniads, 
i. e. from the articular knobs of the inaxillaries to the 
end of the middle caudal rays, the least depth of the 
body varies between 8 and 7 % of its length. The 
variations in our specimens from Bohuslan are such 
that the averages regularly decrease from 8' I % to 7'3 % 
as the length of the body increases from 1G to 37 cm. 
The body as a whole is of the most beautiful fusiform 
shape, the dorsal and ventral contours forming regular 
and similar curves; but the lateral compression is so 
marked that the greatest thickness, which, as we have 
mentioned, lies nearer to the back, measures, in the line 
of the greatest depth, about half — in young specimens 
and after the spawning about 2 / 5 — of the latter. 
The length of the head varies between 22 7 2 and 
1 9 1 / 2 % of that of the body". It is of the well-known, 
three-sided, pyramidal shape that we have already seen 
in the Flying-fishes, but with narrower upper surface 
and with the snout constricted above, in front of the 
eyes. The most characteristic points are the prominent 
tip of the lower jaw and the coat of adipose membrane 
concealing a great portion of the eyes and extending 
both over the sides of the snout and the upper part 
of the shoulder-girdle. This membrane forms two folds 
in front, one composing the anterior limit of the 
orbit, and another the anterior eyelid, which passes 
above without a break into the posterior, growing 
narrower like the latter, but is somewhat broader be- 
low, lying in a fold outside the lower, pointed corner 
of the posterior eyelid, which gradually passes behind 
and below into the adipose membrane of the opercular 
apparatus and the cheeks (the suborbital ring). In this 
latter membrane, which is continuous both with the 
covering of the sides of the snout (the preorbital bones) 
and with the skin of the forehead and occiput, we find 
an abundance of the ordinary ramifications of the lateral 
line, which also occur on the shoulders, though every- 
where less developed than Ave shall find them in the 
Shads. The top of the head, from the nostrils right 
to the occipital crest, as far as the frontal bones extend, 
is coursed on each side by a well-marked lateral ridge, 
bounding a depressed, lanceolate area, dotted with rnu- 
ciferous pores, the tip of the area lying at the occipital 
crest itself. But at the middle of this area runs an 
elevation, in front terete or even mesially depressed, 
behind sharper, Avhicli is formed anteriorly by the above- 
mentioned ridge on the ethmoidal cartilage, and dis- 
appears posteriorly, behind the int-erorbital space. The 
eyes are round, or slightly longer than high, but the 
part free of the eyelids is elliptical, with the upper and 
loAver ends pointed. They are rather large, their longi- 
tudinal diameter varying on an average betAveen 74 and 
7 5 of the length of the head, and being about equal 
in adult specimens to the length of the snout from the 
middle of its tip to the anterior corner of the eye, but 
measuring only about half the postorbital length of the 
head. They are set so high that their upper margin 
approaches close to the frontal plane. The nostrils lie 
on a level Avith the upper margin of the pupil and 
about half as far from the anterior corner of the eye 
as from the middle of the tip of the snout. The an- 
terior nostril of each pair is round and distinct, though 
comparatively small; the posterior more crack-like and 
usually overhung by the adipose membrane belonging 
to the sides of the snout. The two pairs are separated 
by a distance measuring on an average about 2 / 5 of 
the breadth of the snout at the articulations of the 
inaxillaries. The sharp tip of the snout is formed by 
the thin-lipped intermaxillaries, Avhicli strongly remind 
us, both in position and form, of those of the Vendace. 
They are flat but someAvhat arched, triangular, Avith 
the posterior (outer) corner elongated to a point and 
armed on the inner surface of the inferior margin Avith 
a toav of about 6 pointed, incurved (recurved) teeth. 
They are Avithout nasal processes — the tip of the snout 
being consequently not protrusile — and their anterior 
loA\:er corners are rounded to such a degree that they 
are distinctly parted from each other at the middle of 
the tip of the snout. But the sinus thus caused is filled 
by the labial skin, the tip of the snout being thus en- 
tire and truncate, Avithout indentation or groove. In 
“ In the largest Herrings we often find retrogressions to the characters of youlh. In a full female, with the length of the body 
measuring 42 cm. and with eggs 0’8 — 1 mm. in diameter, taken in February, 1887, off Helso (Northern Bohuslan), the greatest depth is 
only 1 6 ' 1 % of the said length. 
6 Varying, according to Lilljeborg’s measurements, between 5 and 7 f. 
c According to our ordinary method of measurement. 
