KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:o I6. 5 
fact that the single species of the genus from New Guinea, described by HEDLEY 
(1897) as F. abdita, was found at a height of 12,200 feet. 
Whether the influence of the tertiary land bridge between Northern Australia 
and New Guinea may be traced in the present distribution of even the marine mol- 
lusca is a question that Mr. Hepiey has drawn attention to, but it is not possible 
to answer it until more comprehensive investigations have given a more complete 
material of facts. On the one hand, there occur a great many mollusca both on the 
east and the west coasts of Australia simultaneously, for which reason the Torres 
Straits seem to have formed the way by which their migration took place. It may, 
however, on the other hand, be questioned whether Torres Straits, the shallowest 
part of which does not exceed seven fathoms in depth, was really used as passage 
by all the mollusca of north-west Australia, which also have a distribution on the 
eastern coast. Some for which an eastern origin is probable, such as Cerithiopsis 
crocea and Gena strigosa might have existed on the north-western coast long before 
the formation of the Torres Straits. Of special interest in this respect are the genera 
Chamostrea' and Ephippodonta, which are lacking on the Queensland coast but appear 
on S. E. Australia on the one hand and N. W. Australia on the other, though in 
different species, it is true. There seems to be also some possibility that the forms 
in question might have spread, on the contrary, along the south and west coasts of 
Australia. 
As to the composition of the marine fauna of N. W. Australia, the present 
collections make evident that the chief part of its constituents have a more or less 
extended range within the Indian Ocean. About three-fourths of them are confined 
to the area between Africa and the Philippines, and only one-fourth are limited to 
the coasts of Australia, such as the species of Pectunculus and Cardita, Chione peronii, 
Turcica maculata, Vermetus novaehollandiae, Strombus campbelli, Voluta oblita. 
The problem of the relations of the mollusc fauna confined to the Australian 
continent has received from the present collections a paleontological contribution, as 
there were found some specimens of extinct land mollusca belonging to genera of which 
a few are not represented in Australia at present, but which show undoubted affinity 
to forms belonging to surrounding districts. They were collected (July 1913) in dark 
caves in the chalky ground at Chillagoe, North Queensland, and comprise the fol- 
lowing new forms: Planispira praehadra, Microcystis antiqua, Hypselostoma australis, 
Aphanoconia extincta, and Omphalotropis minuta. Further, there were found some 
specimens of Microphyura microdiscus, a small shell described by Bavay (1908) from 
the north coast of New Guinea. According to Dr. MséperaG, the caves at Chillagoe 
are excavated in the cretaceous rocks, and are consequently of tertiary age; and 
the mollusca found in them are with certainty relics from this epoch. Unfortunately 
no detailed accounts have been given by Dr. Ms6perc. These finds, therefore, can 
only be simply mentioned here as facts which it is hoped will lead to more com- 
1 Ch. albida Lamarck is recorded from N. S. Wales, Victoria and Tasmania, New Zealand and Chatam 
Island (Hurron 1885, Proc. Linn. Soc. N. 8. W., Vol. TX). 
