GASTEROPODA. 959 
extremely elongated, slender. Inhabits lakes and rivers 
throughout the warmer parts of the world, retiring deep into the 
mud in the dry season, and capable of surviving a drought, or 
removal from the water for many years. In the lake Mareotis, 
and atthe mouth of the Indus, ampullariz are abundant, mixed 
with marine shells. Their eggs are large, enclosed in capsules, 
Fig. 110. Ampuillaria globosa. (Wilton.) 
and aggregated in globular masses. The dentition of A. globosa 
is shown in Fig. 110. 
Distribution, 136 species. South America, West Indies, Africa, 
India. 
Sub-genera. Pomus, Humph. A. ampullacea. Operculum 
horny. : 
Marisa, Gray (ceratodes, Guilding). A. cornu-arietes (Pl. [X., 
Fig. 31). Operculum horny. Shedd discoidal. 
Asolene, D’Orbigny. A. plates. Animal without a respiratory 
siphon; operculum shelly. Distribution, South America. 
Lanistes, Montf. A. bolteniana, L. (Pl. [X., Fig. 32). Shell 
reversed, umbilicated, peristome thin; operculum horny. Dis- 
tribution, West Africa, Zanzibar, Nile. 
Meladomus, Sw. Paludina olivacea, Sby. Shell reversed, 
imperforate ; peristone thin; operculum horny. 
? AMPHIBOLA, Schumacher. 
Synonyms, Ampullacera, Quoy. Thallicera, Sw. 
Type, A. australis (Pl. [X., Fig. 33). 
Shell globular, with an uneven, battered surface ; columella 
fissured ; outer lip channeled near the suture ; operculum horny, 
sub-spiral. Animal without tentacles; eyes placed on round 
lobes; air-breathing; respiratory cavity closed, except a small 
valvular opening on the right side; a large gland occupies the 
position of the gill of paludina; sexes united. (Quoy.) Mr. 
Gray places this genus amongst the true pulmonifera. 
Distribution, 3 species. Shores of New Zealand and the Pacific 
Islands. ‘The living shells sometimes have serpule attached to 
them. (Cuming.) They are caten by the New Zealanders. 
