18 Moll. 
MOLLUSCA. 
giques ” (5G0 pp.)> discusses first the question of species and variety, and 
enumerates the known genera and numbers of species living in the 
Valley of the Rhone, near Lyons, noting their distribution with regard 
to plains and mountains, and land and fresh-water ; also their scarce- 
ness and frequency, and the colonial association of individuals of the 
same, or nearly allied species; he also distinguishes a number of 
peculiar faunulae,” as those of river-banks, rocks, stone- walls, woods, 
gardens, &c., and mentions different examples of acclimatization and 
gradual extension of geographical distribution. He then proceeds to 
discuss the palaeontological representation of the same genera, subgenera, 
and species, chiefly in the quaternary beds, and tries to sketch a history 
of them from those times to the present. In discussing the “ centres of 
appearance,” he approves not only of the three “ centres ” proposed by 
Bourguignat, viz., the Spanish, Alpine, and Tauric centres for the 
European land and fresh-water shells generally, but also proposes a 
larger number of subordinate centres for distinct species, or groups of 
nearly allied species, as for example the French alps for Helix fontenilli^ 
alpina, and glacialis, and adopts the subdivision of the European 
malacological fauna into 6 regions, as proposed by Gr. Fischer, viz. (1) 
the septentrional or Germanic region ; (2) occidental or Atlantic ; (3) 
meridional or circum-Mediterranean ; (4) central or Pontic, extending 
to Austria; and (5) oriental or Caspian. The variations of species are 
studied in detail both for themselves and their causes, which are divided 
into physical (stations, wind, humidity, &c.), chemical (quality of soil, 
saltness of water), mechanical (hibernation, depth and movement of 
water, vegetation), and physiological (nourishment, light, starvation and 
deprivation of air). Finally, the different anomalies and monstrosities 
of shells are discussed. All this is exemplified by a large number of 
very valuable observations, partly made by the author himself in the 
Rhone Valley and its neighbourhood, partly borrowed from other French 
and some foreign authors concerning the same or nearly allied species. The 
author begins and concludes by protesting against the proneness to see 
“ new species ” in mere gradual variations, and to overlook attributes 
possessed in common, in favour of subordinate differences [a warning 
which ought to be addressed chiefly to some of his compatriot concholo- 
gists]. This work may, in short, be called a very useful text-book of the 
more interesting geographical, topographical, and other external relations 
of the European land and fresh- water mollusks generally, though pur- 
posely limited to those of one country, and it would merit this appella- 
tion still more, if the author had been acquainted with some English 
and German treatises with the like purpose. 
2. Scandinavia and Russia. 
Sweden and Norway. 39 species or varieties, new for the fauna of 
these countries, enumerated by A. Westeulund, OEfv. Ak. Forh. 1881, 
pp. 35-50. 
Northern Norway. 14 terrestrial shells found near Bodo, G7° 37' N. 
lat., by the brothers Krause, including Balea perversa (L.) and Clau- 
