MOLLUSCA. 
191 
c. Geographical Distribution and Migration. 
Martens, E. von. Bemerkungen liber natiirliche Gruppirung 
und geographiscbe A^ertheilung der gedeckelten Land- 
sclinecken. [Remarks on the geographical distribution of 
the Pulmonata vperculata.'] Malac. Blatt. 1864, pp. 131- 
144. 
With regard to the contents of this paper, and of another by 
Mr. Blanford, we refer to p. 197, and to p. 237 of the systematic 
part of this Record. 
Aucapitaine, H. Experience sur Bexpansion possible de qnel- 
qnes mollusques terrestres au-delk des eanx salees. Sepa- 
rate publication (8vo, pp. 12) from the Gazzetta uflScialedel 
regno d^Italia. Torino, March 9, 1864; communicated in 
Journ. Conch, pp. 302-304. 
One hundred land -shells were kept immersed in sea- water 
during a fortnight, and twenty-seven of them revived afterwards. 
The presence of an operculum seems to be important in this re- 
spect, as out of twelve Cyclostoma elegans eleven revived, whereas 
of all the other species, which were inoperculated land-shells, more 
than half of the number of specimens subjected to the experiment 
perished, except Pupa cinerea, of which five specimens out of six 
revived (this may be ascribed to the numerous teeth round the 
aperture). It is remarkable that a considerably smaller number 
of the larger species survived the experiment than of the smaller 
ones, and it is especially worthy of note that no specimen of the 
genus Helix, not even one out of six of Helix aperta, shut up by 
their solid epiphragma, stood the test. Notwithstanding these 
experiments, M. Crosse appears to be right in attaching but very 
slight importance, as far as the distribution of the species of Land- 
snails is concerned, to such adventitious occurrences as their fall- 
ing into the sea and being transported by currents to other shores. 
The immigration oiDreissena polymorplia into parts of Europe 
where it was originally unknown, has continued during the year 
1864. Its occurrence in tributaries of the Rhine, Mosel, and 
Main is recorded by Messrs. Noll, Mandel, and Greim (Zoolog. 
Gart. Erankf. 1864, pp. 30, 89, and 124), with the addition of the 
dates of its first detection (1855-61) ; its presence in the middle 
part of the Rhine, at Knielingen near Carlsruhe, is testified by 
Hr. Kreglinger (Verb. ntrw. Verein. Karlsr. vol. i.); its appear- 
ance higher up in the Rhine, near Huningue, where it was found 
by Hr. Seul, is announced by Hr. P. Merian (Verb. ntrf. Ges. 
Basel, iv. 1864, p. 94); and, finally, its immigration into the Loire 
near Orleans, by way of canals, in 1864, has been observed by 
Capt. Morlet (Joum. Conch, pp. 309-314). Towards the end of 
last year the Recorder collected all the facts and observations 
