SPRAT. 
975 
the longitudinal diameter of the eye has proved to vary 
between 31 and 26 % of the length of the head. The 
branchiostegal membrane does not form so distinct an 
angle with the inferior margin of the suboperculum; 
this angle is sometimes almost imperceptible, the poste- 
rior (upper) branchiostegal rays extending further back 
than the interoperculum, and the last of them being 
obliquely truncate at the extremity or produced upwards 
to a blunt point, which is applied to the lower margin 
of the suboperculum. The number of gill-rakers on the 
first branchial arch we have found to vary between 46’ 
and 51, thus fewer than in the Herring. The dentition 
resembles that of the Herring, but is feebler, the teeth 
being often imperceptible, and usually wanting on the 
palatines and vomer, but often present on the ento- 
pterygoid and ectopterygoid bones. The most important 
difference from the head of the Herring consists, how- 
ever, in the comparatively short lower jaw, which is 
always shorter than the base of the anal fin, and the 
length of which varies between about 47 and 5 2 * 1 / 2 % 
of that of the head. The length of the maxillaries too 
varies in the Sprat between 89 and 84 %, in the Her- 
ring between 75 % (in exceptional cases 73 %) and 79 % 
(in exceptional cases 81 %), of that of the lower jaw, 
which is besides perceptibly shorter in the Sprat than 
the distance between its hind extremity and the upper 
angle of the base of the pectoral fin, in the Herring 
equal to this distance or a little longer. 
The dorsal fin is of the same form and occupies 
the same position as in the most developed Herrings. 
At a length of body averaging 88 mm. the average 
distance between the dorsal fin and the tip of the snout 
proved to be 49'9 % of the length of the body, and in 
specimens averaging 120 mm. in length the correspond- 
ing percentage was 50’7. The distance between the anal 
fin and the tip of the snout is somewhat less than in 
the Herring, and varies between about 65 and 71 % 
of the length of the body; but the base of the fin is 
longer, its length varying between 13 and 15 % of that 
of the body. The caudal fin is usually not quite so 
deeply forked as in- the Herring. The length of its 
middle rays is about 6V 2 % of that of the body and 
rather more than V 8 — 2 / 5 of that of the longest rays 
in the inferior caudal lobe. 
The pectoral fins resemble those of the Herring in 
their length as well as in other respects. The ventral 
fins are in general shorter and have fewer rays than in 
the Herring. Their length varies between 9 7 3 and 77 2 % 
of that of the body. Their position affords one of the 
most important characters of the Sprat, the distance 
from the tip of the snout to the anterior (upper) angle 
of the base of these fins extremely seldom — and then 
only slightly — exceeding the length of the body, 
and being less on an average than that between the tip 
of the snout and the beginning of the dorsal fin, rarely, 
and then but slightly, greater than the latter distance. 
It is consequently the rule that the ventral fins are in- 
serted vertically below the beginning of the dorsal fin 
or further forward. The preabdominal length varies 
between 28 and 307 2 the postabdominal between 
about 17 and 22 %, of the length of the body. 
The scales are exactly similar to those of the Her- 
ring, and the most essential difference in the abdominal 
plates has been remarked above. 
The coloration too is so like that of the Herring 
that no constant difference can be adduced. The line 
of lustrous green between the dorsal and ventral colours 
is sometimes ribbon-shaped, rather sharply defined. Ac- 
cording to Valenciennes* this line is sometimes a gold- 
en band; and Collett mentions 0 “a half-grown spe- 
cimen” that had lost its scales, but was marked along 
this part of the sides with two, almost black stripes. 
The geographical range of the Sprat does not ex- 
tend so far north as that of the Herring, but else co- 
incides therewith in the East Atlantic. On the Ame- 
rican side the Sprat has never been found; and Faber’s 
statement* 2 that it occurs off the coast of Iceland is 
not convincing, for he describes its operculum as stri- 
ated, in distinction from the smooth operculum of the 
Herring. But on Gunther’s authority 0 the Sprat has 
been included, together with several other European 
fishes 7 , in the fauna of Tasmania. 
“ 48'3 — 50'4 /, according to our measurements. 
4 1. c., p. 288. 
c 1879, 1. c. 
d Fische Islands, p. 178. 
e Proc. Zool. Soc. Lond. 1871, p. 672. 
I Scicena aquila, Zeus faber, Caranx trachurus, Stolephorus encrasicholus , Conger vulgaris , Orthagoriscus mola, Rliina squatina , Galeus 
Cfinis, Squalus ( Aeanthias ) Blaivvillei, etc. 
Scandinavian Fishes. 
123 
