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walking will crush down a snail shell. But living examples 

 are rare except in very favourable situations ; they are to be 

 obtained by pulling up the bushes by the roots, alongside of 

 which they bury themselves to the depth of an inch or two. 

 Here they may be said to dwell in a moist atmosphere during 

 aestivation, as the dew collected on the twigs, when in 

 sufficient quantity gathers together and trickles down the stem, 

 and thus renders humid the soil immediately about the base of 

 the bush. Bulimus indutus possesses an advantage over its 

 congeners in closing the aperture of its shell by a testaceous 

 epiphragm, which must more securely prevent dessication of 

 the animal than if the aperture were closed by the filmy 

 structure which is formed by the other species. Another South 

 Australian Bulimus, B. Mastersi, which extends westward as far 

 as the sandhills at the head of the Bight, constructs a similar 

 defensive armature. The rarity of living examples of these 

 snails forces one to the inevitable conclusion that the immense 

 numbers f of their dead shells, both on and beneath the surface 

 of the soil, represent the accumulation of centuries of genera- 

 tions. The snails seem to have no enemy ; and in a country 

 where the forces of nature appear to be so equable, the pre- 

 servation of their shells for long periods of time is not a matter 

 for wonder. 



Helix Nullarborica, Bulimus indutus, and B. Adelaides occur 

 over the whole of the Plateau traversed by me. Helix 

 cyrtopleura is also abundant, but more restricted, and, unlike 

 the other species, is confined to the Plateau, where it chiefly 

 affects the rock surface and debris of the western part of the 

 Bunda cliffs, and about the caverns and stony ground inland. 

 Pupa australis occurs over much of the better lands. All the 

 above, excepting Helix cyrtopleura live in the sandhills at the 

 head of the Bight, at Mundyarra, near "Wilson's Bluff, and at 

 Eucla, where they are accompanied by Helix arenicola, Tate, 

 and Pupa Maryarettee, species not seen on the Plateau. Of the 

 above species Bulimus indutus is an addition to the South Aus- 

 tralian fauna, and Helix Nullarborica is new to science. 

 Bulimus Adelaide, Pupa australis, and Helix arenicola are the 

 most widely diffused of our land snails. 

 Marine Conchologt abound the Head of the Great Bight. 



The littoral life in these waters is that which prevails on the 

 rough water shore throughout the southern coast of the con- 

 tinent. The species are few in number, though individuals 

 abound. The majority of them are characterised by thick 

 tests. Judging from the shells cast up upon the limited beach- 

 line facing the ocean, the laminarian and deeper water forms 

 are not so numerously represented as in the qiiiet waters of 

 Fowler's, Streaky, and other bays. 



