ZARTI-IE. 
801 
the females between 14 and 15, in the males between 
15 and 16". In relation to the dorsal fin they lie so 
far back that the distance between their insertion and 
the tip of the snout is as a rule perceptibly more than 
87 % (87 1 / 3 — 947 2 %) of that between the dorsal fin 
and the same point. 
The scales are middle-sized, deeply embedded in 
the skin, and imbricated. They are of an irregular 
quadrilateral shape and rounded, with almost central 
nucleus, dense concentric striae, and numerous and Avell- 
defined radiating grooves, the latter alternating, both 
in front (finer) and behind (coarser and more regular), 
in their greater or less extent tOAvards the nucleus. 
In coloration two varieties are distinguished * * 6 , Nek- 
vimma (Pale Zarthe) and svartvimma (Black Zarthe), 
the latter being probably no more than the spaAvning 
dress. Both on the head and the back the coloration 
is above blue or greenish broAvn, at the top of the sides 
of the body silvery with a dash of blue, fading beloAv 
into the pure silvery white of the belly. On the sides 
of the head the dark blue tint extends down to the 
upper part of the gill-cover, and the silvery lustre 
sIioavs stronger or fainter traces of a brassy colour. In 
Germany its dark snout has gained for the Zarthe the 
name of Blaunase or Bussnase. All the fins are light, 
gray or grayish blue, more or less tinged, especially 
the caudal, Avith orange at the base. The iris is of a 
pale brassy yelloAv, shading into greenish above the 
pupil. Our figure, Avhich is coloured from a sketch by 
W. v. Wright, represents the Zarthe in this dress of 
almost pure silver. On weedy bottoms or in dark 
water the colours of the fish are greener with a more 
powerful brassy lustre. Siebold has described the dark 
spaAvning dress, in Avhicli the sides of the body, even 
beloAv the lateral line and close to the ventral and anal 
fins, acquire a singular silky lustre, this being caused 
by a deep black pigment from Avhich the ventral side 
itself, from the lips to a narrow strip at the margin 
behind the anal fin, stands off sharply Avith its deep 
orange hue. The latter colour also extends to the 
paired fins and the base of the anal fin; the dorsal and 
caudal fins, the upper margin of the pectorals, and the 
loAver margin of the anal fin being, on the other hand, 
blackish. In addition to this spaAvning dress, Avhich is 
common to both sexes, the males are distinguished at this 
season by the usual dermal eruption, consisting of small 
round tubercles on the occiput, the opercula, the margins 
of the scales, and the inner surface of the paired fins. 
The Zarthe is properly a marine fish, but also lives 
in the great lakes, and ascends rivers in order to spawn, 
being thus a so-called anadromous species. Its geo- 
graphical range comprises Eastern Europe from Finland, 
SAveden, North-Avestern Germany, and the Avatershed of 
the Danube to the Black Sea Avith its Russian river 
systems and the Sea of Azov. It makes its Avay up 
the Elbe and Weser from the North Sea, but is Avant- 
ing in the Rhine. In Finland, Avhere it is common 
among the southern islands and, to the east, in Lake 
Ladoga, it does not go farther north, according to Mela, 
than the sixty-third degree, being very rare even in 
that latitude. From the SAvedish coast of the Gulf of 
Bothnia Ave are told by Widegren (1. c.), though his 
statement is perhaps questionable, that the Zarthe oc- 
curs in the loAver course of the Lulea Elf (nearly 66° 
N. lat.). The northernmost locality in Sweden to which 
Ave can Avith certainty assign this species, is the neigh- 
bourhood of Hudiksvall (about 62° N.), from Avhich 
region Mr. Wistrom has sent to the Royal Museum a 
specimen 24 cm. long, taken in the fjord of Lingaro 
on one of the last days in September, 1882. In the 
same neighbourhood, Ave are told, it sometimes, though 
seldom, ascends the River Dekanger in spring. Ever 
since Nilsson’s time the Zarthe has been knoAvn in 
Blekinge; but in Scania it has never been found. It is 
commonest in the Malar Valley and the Baltic island- 
belt Avith the streams that fall into this part of the 
Baltic. In Lake Wener it is also found, and is some- 
times caught, “especially in the months of May and 
June” (Malm) in the River Gotha at Gothenburg. In 
Nonvay, Denmark, and the Avest of the Baltic the spe- 
cies is unknoAvn; but from the Elbe it Avas described 
even by Gesner and Schonevelde. From the Baltic 
it enters the German Haffs to spaAvn. According to 
Dybowski (1. c.) and Seidlitz c it occurs in all the riv- 
ers of the Baltic Provinces of Russia. Its Baltic range 
being of such extent, Ave might Avell expect to find it 
both off Gothland and Bornholm; but is has not yet 
been observed in either of these localities. 
a According to Dybowski the same sexual distinction was present in his specimens; but the percentages are somewhat lower, this 
being probably due to a different manner of measurement. 
6 According to Mr. Arosenius, who forwarded to the Royal Museum specimens of these varieties from the Motala River (Norrkoping) in 1834. 
c Fauna baltica , p. 101. 
