114 MANUAL OF THE MOLLUSCS. 
the clouds discharge themselves on the east side of the Andes, 
and rain is so rare on the west coast that in some parts it only 
falls two or three times in acentury. In Peru, during great 
part of the year, a vapour rises in the morning, called the 
‘“‘garua;’’ it disappears soon after midday, and is followed by 
heavy dews at night. 
Mr. Cuming collected 46 species of land snails in Peru; and 
Dr. Pfeiffer enumerates 100, but perhaps half the latter were 
from the eastern side of the Andes, belonging to the Brazilian 
Province. They are mostly Bulimi, and are smaller and less 
richly coloured than those of Bolivia and Brazil; B. Denicket, 
solutus, and turritus are peculiar forms. Cistula Delatreana is 
the only operculated land snail, and Vaginulus limayanus the 
only slug. 
JBRSIb-< egncagdondndonsac0N 12 12YNGG: coonecaqqnonco000000¢ 1 ANIGYUS!sancenmeesecte ser 1 
ES WMTUS Nos. ccc semeeee eres 79 ale aeeadeesersesteeeeee 1 Ampullariateeesesnees 1 
SUGCCINC Aue. deancecesss 5 CHS, sonnca39s500000000 1 Paludestrina...... ..... 2 
Glandinae..s.-ss.sss=s 1 1 BRR YEE pacaqn060600300300000 1 (OAH ESE), Goonqsso0n0-05.0- 3 
Tornatellina .......0600+ 1 Plan Orpisesssss 4p esses 3 AnNOO On assessepeseeeenae 1 
25. ARGENTINE REGION. 
The ‘‘ region of arborescent Composite’”’ has afforded scarcely 
any land snails; only 7 species of Bulimus, and 3 Helices are 
recorded, but some others may have been included with those 
of Brazil and Chili. From Bolivia this province is separated 
by the wide plains of the Great Desert, or northern prolonga- 
tion of the Pampas; and all the eastern part has been submerged 
at a recent (geological) period; so that the only promising 
districts are Paraguay and the eastern declivities of the Chilian 
Andes. The fresh-water shells of the La Plata and its tribu- 
taries are more remarkable. 
Cnt ono pnosanonnpacee UY GYGES coos adanasdaac 1  Byssoanodon cevseesse 1 
PAANOUDIS) aeeasceceseres il Pisidium ..... B Yate od 1 Monocondylea.......0« 6 
JSST W ITS) cacpegonesacog 2000 4 Corbicula ..........0000. 2 Mycetopus .......0+00» 1 
Ampullaria ....:..000+ 7 UNION Seecsssessverssesesse tf Castalia, .:.ccs00sssssess 1 
MASOIENC vescecesesecevaxes 1 ANOMONsseseeceaceotentes 10 IGE LI pacnncnnantic8 190 1 
Paludestrina...... ...+. 7 
Ampullaria (Marisa) cornu-arietis is a characteristic shell; 
Paludestrina lapidum has a claw-like (non-spiral) operculum, 
and appears to belong to the Melaniade. 
26. CHILIAN REGION. 
The northern part of Chili belongs to the same physical region 
with Peru, consisting of dry and rainless plains. Here the land 
