106 DISCUSSION. 



pressure of 95 pounds on the square foot, as just mentioned by 

 me, in order to overturn a railway engine, and other instances of 

 like kind ; but it is more than probable that the force exerted by 

 the wind in a tornado, which breaks off large trees 18 inches in 

 diameter, is much greater, but it has never been measured. 



Mr. Mann : — I was in a storm many years ago. I saw it 

 coming up from the southward. I took refuge in my house. 

 There was a large tree at the northerly end of the house. The 

 cyclone twisted this tree and it fell to the southward. It fell 

 over the house and smashed everything to the ground. I went 

 to the door and got out. A quarter-of-a-mile off there was a 

 camp of black fellows. Their gunyahs were upset. The storm 

 went on and twisted the head off one of the gigantic trees three 

 or four feet in diameter, and the head of the tree which must 

 have weighed 200 tons, was suspended in the air off the ground 

 before it came to the ground. 



The President : — We are much indebted to Mr. Russell for 

 his paper and the interesting discussion it has evoked. As the 

 time is going on, I will now call upon the Hon. Secretary to read 

 the next paper. We are all sorry to feel that the author of this 

 next paper is an invalid, and suffering from the injurious effects 

 of his travels, and therefore unable to be present. 



ON THE ANATOMY AND LIFE HISTORY OF MOLLUSC A 



PECULIAR TO AUSTRALIA. 



[With Plates.] 



By Rev. J. E. Tenison-Woods, F.L.S., F.G.S. 



iBead before the Royal Society of N.8.W., July 4, 1S8S.1 



The Mollusca of the Australian coast are sufficiently peculiar to 

 entitle the region to be considered a geographical province. Yet 

 it must be acknowledged that the distinction, though well marked 

 in some respects, is not so peculiar or abnormal as in other sections 

 of the Animal or Vegetable Kingdom. The exceptional characters 

 of the land mammalia, for instance, are truly extraordinary, while 

 of the flora it may be said that volumes have been written about 

 it, and yet volumes must still be written ere the subject be fully 

 unfolded. In the seas and in the rivers, in other departments of 

 the Animal Kingdom multitudes of marvels meet us, all of so 

 strikingly an anomalous kind, that Australia well deserves to be 

 considered a Zoological region, singularly apart from the rest of 



