It is evident from the comparative paucity of undescribed species procured in the Littoral zone and the large proportion of new or doubtful forms among those taken by the dredge, that a rich harvest has yet to be reaped in the deeper regions of the southern seas.  In the lower zones, however, just as much as in the upper, the distinctions of province are maintained.  The explanation of this complete separation of the South-eastern marine fauna of Australia from that of the North-eastern or Indo-Pacific portion, may be explained by reference to the distribution of currents along the Australian shores.  In both, as in the Bathymetrical regions of the South Atlantic, the Testacea of the depths are generally smaller and less brightly coloured than those inhabiting the shallows.

During this voyage notes of the habitats of considerably more than a thousand species of Mollusca and Echinodermata were carefully registered.

2.  ENUMERATION OF TERRESTRIAL PULMONIFEROUS MOLLUSCA AS YET NOTICED IN AUSTRALIA.

The following Catalogue is founded on the monograph of Helicidae by Dr. Pfeiffer.  To the species therein described are added certain new ones, announced by Pfeiffer since the publication of his work, and others, recorded for the first time in this volume.  It will be seen that a great part of the Australian land-shells is as yet unfigured.  The exact localities of not a few have to be determined; a precise record was kept of the place and circumstances under with each was found during the voyage of the Rattlesnake.  From all we yet know the genus Helix is fairly represented in New Holland, and presents some very remarkable and peculiar forms; Bulimus has but few, and those (with the sole exception of B. atomatus) not remarkable Australian members; a single Pupa, closely resembling one of our commonest European species, is the only recorded Australian one; and a very remarkable addition to the terrestrial conchology of the southern hemisphere has been made in a Balea of a type unlike any other member of the genus.

HELIX.

1.  H. falconari, Reeve. (Conch.  Syst. t. 163, f. 4).  Locality:  Bellingen River, in the brushes (Macgillivray).

2.  H. irradiata, Gould.  Locality:  New South Wales.

3.  H. australis, Menke.  Locality:  Swan River.

4.  H. georgiana, Quoy and Gaimard.  Locality:  King George’s Sound.

5.  H. novae hollandiae, Gray.  Locality:  Macquarie River.

6.  H. jervisensis, Quoy and Gaimard. (Voyage Astr. 2 t. 10, f 26-30).  Locality:  Jervis Bay (Quoy and Gaimard).  Brisbane Water, under logs in dry, stony, and scrubby ground (Macgillivray).

7.  H. subgranosa, Le Guillou.  Locality:  North Australia.

8.  H. capillacea, Ferussac. (Hist. t. 82, f. 5).  Locality:  Port Jackson (Ferussac).

9.  H. jacksoniensis, Gray.  Locality:  Port Jackson.  May not this be H. nitida introduced ?

10.  H. walkeri, Gray.  Locality:  New Holland.