389 



wa3 being carried on by Prof. Bragg, and which would pro- 

 bably revolutionize many of the scientific ideas of to-day. 



Ordinary Meeting, May 5, 1908. 



The President (J. C. Verco, M.D., F.R.C.S.) in the 

 chair. 



Ballot. — J. P. V. Madsen, D.Sc, B.E., Lecturer at the 

 University of Adelaide, and W. Noel Benson, B.Sc, Lec- 

 turer at the University of Adelaide, were elected Fellows. 



The President laid on the table a letter from Mr. Dod- 

 well, of the Commonwealth Meteorological Department, in- 

 viting Fellows and members to the Observatory to inspect 

 the seismograph which was being installed there. 



Exhibits.— Mr. J. G. O. Tepper, F.L.S., laid on the table 

 a bound volume of "Separata" of descriptions of new Australian 

 plants not contained in Bentham's ''Flora Australiensis," by 

 the late Baron Ferdinand von Mueller. Mr. Tepper also 

 exhibited a trombone, showing the work of larvse of Aulaco- 

 yhoru hilaris (Boisd.), a small beetle of the Family Chryso- 

 melidce. A leaf covered with web of Sfenopsocus stigmaticuSy 

 a species of the Family Psosiche (CopeocinathidcE), which in- 

 fests many trees and plants without seemingly being injurious. 

 The mature insect is l-20th of an inch across open wings, be- 

 longing to the same Family as the wingless and spring-tails, 

 the latter found in pools after rain. Male and female galls 

 of Brochifscelis ovicoloides, a grenus of Coccidae. Dr. Pul- 

 leine exhibited a trap-door spider of very unusual appear- 

 ance, possibly a new species. From a sketch on the black- 

 board Dr. Pulleine showed the peculiar shape of the cephalo- 

 thorax and the position of its eight eyes. 



Papers. — ''Notes on the Geology of the Mount Lofty 

 Ranges, chiefly the portion East of the Onkaparinga River," 

 by W. G. Woolnough, D.Sc, F.G.S., University of Sydney; 

 "An Experimental Investigation of the Nature of the Gamma 

 Rays," part ii., by Prof. AV. H. Bragg, M.A., F.R.S., and 

 J. P. V. Madsen, D.Sc. In the discussion which followed 

 the reading of Dr. Woolnough's paper, Mr. Howchin stated 

 that he could not agree with the author's generalization on 

 the geology of the Mount Lofty Ranges, and particularly in 

 relation to the geological section which Dr. Woolnough had 

 made from Mount Lofty to the River Murray. The section 

 showed the Mount Lofty Ranges to consist of a monoclinal 

 series of beds, the older members being on the west and the 

 newer on the east. No such regular succession of beds ex- 

 isted, as the series was broken by the exposure of an im- 

 portant pre-Cambrian axis, from which the beds dipped west 



