Dt L SOÓS 
458 
the Tátra. The individuals found here attain to a relatively large size, 
and the shell forms a conically tapering spire, its apex protuding so 
high that its hight and diameter are quite equal. 
The Neritina species of the thermal springs of Tapolcza, is known 
as N. Prevostiana var. hungarica (Este.) Mets, which differs, according 
to Kobelt, from the typical ones, in its taller spire, and in the aperture 
of the shell beeing somewhat more elongated. 
I could not however discover any increase in its height of the 
spire in comparison tho that of the forms generally considered as typical, 
but it differs from them in that the last whorl often shows no traces 
of subangulation, and in that the shell is more elongated in the direction 
of its longer diameter, approaching thus the Sicilian species, N. meri¬ 
dionalis. It is remarkable that its black ground colour is often varie¬ 
gated with brighter spots arranged in transverse rows, which is, in 
turn, characteristic of one of the southern species, A. peloponnesia. 
The forms occurring at Tata and Yoeslau are uniform in shape 
but, in what regards coloration and marking, the differ in a high 
degree. Contrary to the black Yoeslau specimens, the ground colour 
of the former varies from a light, to a deeper, mauve which is either 
uniform throughout or dappled by bright patches uniting as a rule in 
irregularly undulating lines, or into regular zig-zag stripes. 
Forms with these zig-zagged streaks, and N. danubialis are nearly 
uniformly marked; this is why the specimens collected by Hazay at 
Tata received from him the erroneous name of N. danubialis var. ther¬ 
mulis. It is beyond question, however, that the two forms cannot be 
identified, unless incorrectly, with eachother, since N. danubialis belongs, 
as mentioned above, to those Neritvnae (i. e. the group of N. fluviatilis), 
which are larger in size and greatly elongated along their larger diameter. 
In spite of the deviations in marking, I am looking, with Brusina, 1 
on the Tata species as Ai Prevostiana, the missing link between the 
Yoeslau black, and the Tata zig-zaggedly striped, forms being fur¬ 
nished by the lilac specimens occurring at either place. Brusina remarks 
that the form of N. Prevostiana, which occurs at Podsused, near Zágráb, 
also shows occasionally some signs of this zig-zag strigation. 
Living Neritinae have not been found recently in the Püspök¬ 
fürdő though they did undoubtedly occur there in the first years of the 
seventies as is amply born out by the fact that specimens of them 
collected by Messrs. A. Mocsáry and J. Hazay, are still in the collection 
1 Eine subtropische Oasis in Ungarn. (Mitth. Naturw. Ver. Steiermark. Jg. 
1902. p. 117.) 
