114 
MOLLUSCA. 
In districts either poor in, or devoid of, limestone, the 
shells of snails become very thin and pellucid, and very often 
the living animals gnaw the shells of their fellows, even to a 
highly injurious degree, in order to procure carbonate of lime ; 
the shells of the Clausilice are shorter than usual; Helix laptcida 
is rather rounded in the periphery ; and several species are en- 
tirely wanting. The pale-coloured or albino varieties, however, 
are not due to this cause, but, on the eontrary, are often to 
be found rather copiously in regions abounding in limestone. 
Id. CB. Ver. Regensb. xxvi. pp. 50-58. 
Helix ncmoralis, var. pallida (an albino form), and a scalariform specimen 
of the same (figured). Ins Comte, Bull. Mai. Belg. vii. pp. xxvii k xxviii. 
Specimens of Helix hortensis of a peculiar brownish hue found near tan- 
neries by Tischbein, Nachr. mal. Ges. 1872, p. 44. 
Limncea stagnalis. Rose-coloured specimens and a variety with two 
pillar-plaits. Colbin, Bull. Mal. Belg. vii. p. xliii. — Specimens with appa- 
rently doubled tentacles. Id. ibid. p. lii. — Sinistral specimens and others of an 
hereditary yellow colour. Id. ibid. p. lx. 
Shell of Limiusa stagnalis damaged by others of the same species gnawing 
it to get calcareous matter. Wieciimann, Arch. Ver. Mechleiib. xxvi. 
pp. 95-97. 
The living animal of Helix arbastorum observed destroying its own epi- 
dermis by gnawing. Kobelt, Nachr. mal. Ges. 1872, p. 44. 
Clausilia biplieata (Mont.) txndi plicalida (Drap.). Several specimens with 
a double peristome were found in June 1872, on the same spot, by S. Clessin, 
who considers that the rainy weather of the season enabled the animals to 
continue their growth without interruption. Mal. Blatt. xx. pp, 68-61, pi. 4. 
figs. 1-3. 
GEOGRAPHICAL DISTRIBUTION. 
a. Land and Fuesuwateu Mollusc a. 
1. Northern and Central Europe. 
Norivay. O. S. Jensen gives an account of land and fresh- 
water mollusks observed during a summer journey in the two 
southern provinces of Norway, Christiania and Christiansand, 
adding 31 species to those enumerated about 20 years ago by J. 
Trielc. The slugs, as well as the small species of Pupa and 
Pisidium, are treated with special care. N. Mag. Naturv. 1872, 
pp. 14G-188. 
United Kingdom. Land and freshwater shells collected in Ireland and 
Wales by J. Lindahl are mentioned by 0. Westeblund, Nachr. mal. Ges. 
1872, p. 26. 
Belgium. The following lists of land and freshwater Mollusks are pub- 
lished in Bull, Mal. Belg. vii. : — by M. Pibe, 69 species from the province of 
Liege, pp. vii-xj by M. Collin, 24 from the Bupel, a tributary of the Scheldt, 
