104 MANUAL OF THE MOLLUSCA. 
cipally to East Australia. He notices, Helix 133, Vitrina 17, 
Succinea, 12, Bulimus 17, Pupa 6, Balea 1, and others belonging 
to genera Triboniophorus, Limax, and Planorbis. ; 
13. SoutH AUSTRALIA AND TASMANIA. 
From extra-tropical Australia we have the following :— 
Helx 9, Helicarion 2, Bulimus 2, Succinea 1 (common to Swan 
River and Tasmania), Limax olivaceus, and one Ancylus. Two 
of the largest land snails, Helix Cunninghami and Falconeri, are 
found in New South Wales. The coasts of this region are 
thinly wooded, but much of it is rendered desert by want of 
rain; in New South Wales droughts recur at intervals of twelve 
years, and sometimes last three years, during which time scarcely 
any rain falls. 
14. NEw ZEALAND. 
The moist and equable climate of these islands (which have a 
mean temperature of 61°—63°) is favourable to the existence of 
numerous land-snails. Nearly 100 species of land and fresh- 
water shells are already determined, and are all peculiar; the 
genus Helix musters 60 species, some of which, including the 
ereat H. Busbyi, resemble in shape the European Helicellae ; 
Bulimus 3, Balea (peregrina), Vitrina 2 of peculiar form, Tor- 
natellina 1, Cyclophorus cytora, and Omphalotropis egea, 
There are two slugs, Limax antipodarum and Janella bitenta- 
culata; two fresh-water pulmonifera, Physa variabilis and Latia 
neritoides ; several marine air-breathers,—Oncidium (Peronia) 2, 
Siphonaria 38, Amphibola 1 (avellana). The other fresh-water 
shells are Melanopsis trifasciatus (a Lusitanian type), Assiminea 
antipodarum and Zelandize, Amnicola? corolla, Cyclas Zelandize, 
and Unio Menziesu and Aucklandicus. 
Vitrina zebra is found at the Auckland Islands. 
15. POLYNESIAN REGION. 
The Pacific Islands are partly the yoleanic summits of sub- 
merged mountain ranges, usually fringed or surrounded with 
coral reefs; and partly atolls or lagoon islands, scarcely rising 
above the sea, and presenting no vestige of the rock on which 
they are based. The low coral islands form a long stream of 
archipelagos, commencing in the west with the Pelews, Caro- 
lines, Radack, Gilbert, and Ellice groups, then scattered over a 
wider space, aud ending eastwards in the Low Archipelago: 
