HUNGARIAN NERITINÆ. 
457 
with in that place, nor, though inhabiting nearly all countries of Europe, 
is it living in the Danube or its tributaries except a few ones coming 
from Bavaria. We may take it for granted, accordingly, that it does 
not occur in those parts of Hungary which belong to the riverbasin of 
the Danube. It does occur, however, as recent investigations show, at 
the Hungarian shores of the Adriatic (Sv. Juraj, near Zengg). The form 
found here was described by T. Kormos as N. fluviatilis L. var. zer- 
novnicensis. 1 Besides this, it occurs also in another place south of 
Sv. Juraj. Forms found here, are said by M. Kormos to be identical 
with N. fluviatilis L. var trifascidta Villa. 
It is well known, too, that N. danubialis and N. transversalis live 
both in the Danube and its affluents, the latter living, however, in its 
left-hand tributaries only, while Martens’ statement 2 of the former 
not being found in these, ist obviously incorrect, for it may readily be 
met with, among others, in the lower courses of the Nyitra, Karas, 
and Néra. 
A typically developed N. Prevostiana may be easily distinguished 
from the three species mentioned above, from even N. danubialis, to 
which it is most nearly allied, by its smaller size and its thickly set, 
shorter body, in contrast to which the former invariably display more 
delicate, and almost always larger, forms more elongated along their 
transverse diameter. — N. Prevostiana lives, one particular case excepted, 
in warm, while the rest inhabit cold, water. 
Outside the boundaries of Hungary, it lives nowhere else, except 
in Voeslau (Austria), where it was for the first time described to occur. 
The Voeslau specimens are small, subglobose, of an entirety black, 
rarely lilac, colour, with a feebly developed ridge along the upper part 
of the last whorl. Black ones are found at three places in Hungary, viz. 
Bobogány (county Bihar), Tapolcza (near Miskolcz) and the Tátra 
Mountains. 
The specimens found at Bobogány, differ from the Voeslau forms 
only in that the spire of the former specimens is very short and nearly 
flat. Besides, there is an arched groove situated on the last whorl 
between the ridge and the suture. 
A good deal of interest will be furnished to the observer when 
he turns to investigate those forms which are met with in the icy-cold 
springs of the waterfalls down the steep «Drechselhäuschen» slope in 
1 Beiträge zur Mollusken-Fauna des kroatischen Karstes. (Nachrbl. Deutsch. 
Mal. Ges. 38. Bd. 1906. p. 153.) 
2 Die Gattung Neritina (in: Martini-Chemnitz. Conch. Cab.) 
