110 ANATOMY AND LIFE HISTORY OF MOLLUSCA. 



tropical shells belonging to the Malayan region, have been 

 dredged in Port Jackson.* The well known tiger-cowry (Cyjyrcm 

 tigris, L.), C. arabica, L., and C. vitellus, L., all come within a 

 short distance of Port Jackson, though they are not common. 

 C. annulus, L., I have found on the extreme south coast of 

 Tasmania. 



On the west coast of Australia, the influence of the tropical 

 seas extends much further to the south, and though as the 

 south-west Cape Leuwin is approached the Australian element 

 begins to manifest itself, the general character is tropical with 

 the Indo-Malayan elements predominating. This need not 

 surprise us, when we find that such a typical tropical shell as 

 Fusus colosseus, Lamarck, occurs at Swan River, W. A., and 

 regular reef-buikling corals form the dangerous reef of Houtman's 

 Islands (S. Lat. 28° 30' about). A collection of shells from the 

 neighbourhood of Swan River contains so large an admixture of 

 forms common to the Indian Ocean, and so few proportionately 

 peculiar to Australia, that the region can hardly be said to belong 

 to other than the very boundaries of the Australian Province. 



The characteristic Australian fauna in the Marine Mollusca is 

 best seen between the Australian Bight and the extreme eastern 

 end of Bass' Straits. It is also found in Tasmania ; probably 

 more typically there than in any other seas. 



The characters of the Australian region may be thus described : — 

 The possession of peculiar genera, such as Strut1dolaria t 

 Macrochisma, Macgillivraia, Amphibola, Trigonia, Chamostrea, 

 Myadora, and Myochama. The above are not found beyond 

 Australia and New Zealand. 



The possession of peculiar forms of well-known genera, or else 

 genera which, if found elsewhere, are only sparingly represented 

 or rare ; such as Phasianella, Elenclius, Bankivia, Hotella,\ 

 Scutus, Fisella, peculiar and abundant volutes, Fasciolaria, Crossea, 

 Siphonaria, Gadinia, Anatina, Anatinella, Pandora, Crassatella, 

 Cardita, Cypricardia and Mesodesma. 



To these must be added the Brachiopoda, which are perhaps 

 better represented in Australia than in any other region. They 

 include Terebratula, Terebratulina, Waldheimia, Terebratella 

 (fossil only ?), Magassella, Megerlia, Krausinia, Lingula (three 

 sp.), &c. 



The survival of the genus Trigonia has already been dealt with ; 

 but it derives a greater interest from the fact that we find Trigonia 

 represented in tertiary strata by different species from those at 



* J. Brazier, Proc. Lian. Soc, N.S.W., Vol. iv., p. 428. 



f Found also in India, the Philippines, China, and very common in 

 Japan, but in the Southern Hemisphere confined to New Zealand, and 

 therefore not strictly speaking Australian. 



