644 
operculate genera Fupina, Selioina, and Diplommatina is stared by tbe inoperculate 
forms of Aiopos, Sadra, CMoritis, and Papuina; A. prismaticus of Papua claiming 
affinity with A. australis of Queensland, li. Broadhenti with H. inforviis, O. cJiloritoides 
with G. Porferi, and P. nasn with P. ALacgilli'erayi. The species actually common to 
both regions are few ; B. MacJeayi inhabits boih countries, T. annula only finds a place 
in the Queensland catalogue by courtesy, while P. pedieula, S gracilis, T. ceylanica, 
T. valida, and L. vitreum are widespread throughout Polynesia. From these premises 
it may be deduced that this portion of the Queensland molluscan fauna, though isolated 
sufficiently long to have lost specific identity with that of Papua, has nevertheless been 
derived from it. 
“ The shallow sea of Torres Straits now severs this Continent from the 
adjoining Island. Were its bed raised but seven fathoms the tw'o countries would be 
united, while an elevation of ten fathoms would form a wide bridge between them. 
When the marine life east and west of Torres Straits is better known it will be of 
interest to observe whether the influence of an ancient isthmus is still visible in any 
divergence between the fauna inhabiting the two areas. 
“ Further to the westward the coasts of Australia and New Guinea again converge, 
being separated by an arm of the Arafura Sea, which gradually shoals from a central 
depth of forty fathoms, and stretches for about a hundred and fifty miles between Cape 
Wessel in the Northern Territory, and Cape Valsche on the opposite shore of Dutch 
New Guinea. 
“ In the ‘ Transactions of the Eoyal Society of S. Australia’ (vol. v., 
pp. 47-56), Professor Tate enumerates the Land and Freshwater Mollusca of 
tropical S. Australia. It is remarkable that whereas a third of the land shells of 
Papua, and a sixth of the land shells of Queensland, are operculate, his census 
includes no operculate land shells whatever. Thus, at the remote date when the 
ancestors of the present Queensland molluscan fauna migrated from New Guinea 
across the ancient isthmus that I suppose to have bridged Torres Straits, the 
Arafura Sea appears to have still presented an impencti’able barrier between the two 
countries. The former elevation of land in this region, if uniform from east to west, 
may therefore be calculated at more than seven and less than forty fathoms.” 
Family— LIMNiEID^. 
Genus — LIMPf^A, Lamarch, 1799. 
(Prodrome — M^m. Soc. Hist. Nat. Paris, 1799.) 
Amphipeplea vinosa, A. Adams and Angas, Proc. Zool. Soc., 1863, p. 415. 
Limnwa (Amphipeplea ?) vvnosa. Smith, Journ. Linn. Soc. (Zool.), 1883, xvi., p. 273. 
„ rinwsa, Daintree, Quart. Journ. Geol. Soo., 1872, xxviii., Pt. 3, p. 274. 
Ohs. The name Limncca rimosa, given in Mr, Daintree’s Paper, probably refers 
to this species. 
Loo. and Horizon. Maryvale Creek, Clarke Eiver, North Queensland {The 
lale JR. Daintree) — Diprotodon-hreccia. 
Genus — PHYSA, Draparnaud, 1801. 
(Tab. Moll. Terr. Pluv. Prance.) 
Phtsa. teuhcata, H Adams. 
Physa {Ameria) truncata, H. Adams, Proc. Zool. Soc., 1861, p. 144. 
„ truncata, Daintree, Quart. Journ. Geol. Soc., 1872, xxviii., Pt. 3, p. 274. 
„ {Ameria) truncata, Smith, Journ. Linn. Soo. (Zool.), 1883, xvi., p. 292. 
Loo. and Horizon. Maryvale Creek, Clarke River, North Queensland {The late 
JR. Daintree) — Diprotodon-breccia. 
