132 Transactions. 
It will be admitted that every stream draining a forest-covered country 
carries on its waters, especially at times of high flood, some of the animal- 
life whose habitat is the ground. Almost the whole of our land Mollusca 
shelter under fallen timber and amongst the leaves and decaying debris. 
An exceptionally torrential rainfall would scour hillsides and gullies, and 
carry to the main stream very considerable quantities of loam and debris, 
together with the animals inhabiting it. e have only to view some of 
the large rivers, such as the Wanganui when in high flood, to gain a clear 
conception of the vast toll gathered from the forest lands: its surface is 
strewn with huge logs, freshly uprooted trees, and masses of debris, the 
water charged to its maximum carrying-capacity with loam and sandy clay. 
This continues for hours, and in a lesser degree for several days: on entering 
the sea it forms a great fan of discoloured water extending to the horizon. 
In such a flood immense numbers of the land-snails must have shared the 
fate of not a few of the higher animals, yet they leave little record on the 
beach. A careful search may reward the collector with a few specimens 
у. 
Almost the whole of our land-shells are very fragile, and no doubt the 
pounding they receive in the surf is sufficient to destroy them. This, how- 
ever, does not appear to be the sole cause of their non-preservation : there 
are large streams flowing into well-sheltered bays and harbours, and each 
deposits its quota of land-shells in the protected waters. During Tertiary 
and Cretaceous periods, we may reasonably assume, innumerable similarly 
situated streams must have existed, but, so far, little record of the land 
molluscan fauna has been found in the rocks. The shells as a whole are 
constructed of a very thin calcareous deposit, and when the epidermal 
conchin is destroyed they are in a condition readily to disintegrate. A brief 
period of immersion in water is sufficient with most of our species to destroy 
the epidermal coating. 
held the storm-water and silt from the land close on the shore-line, and 
that it was not subjected to a heavy surf. No doubt the bed extended 
considerably along the shore and only a fragment is preserved. 
We are informed by a resident who occupies land several miles nearer 
be desired that a careful investigation of the coast-line be made between 
the Taieri River and the Akatoa Creek. 
List or LAND MoLLUSCA. 
Aeschrodomus barbatula (Reeve) Phri | 
1 zgnathus cela Hutt. 
скы planulatus (Hutt.) Phrizgnathus pumila (Hutt.) 
aropa (“ Саена”)  biconcava Ptychodon suteri Murdoch and Finlay. 
var. minor Sut T halassoheliz igniflua (Reeve) 
Charopa (“ Fectola”) otagoensis Sut. | Therasia thais-. Hutt 
Charopa (“‘Fectola” ) tapirina (Hutt.) eee 
