157 



A discussion followed, in wliicli several questions were put 

 to and answered by Mr. Todd, cliiefl}'' relative to theories 

 extant with respect to the constitution of comets and their 

 motions. 



2. " On South Australian jSTocturnal Lepidoptera," bj Dr. 

 W. H. Gaze. (For abstract and discussion see p. 141.) 



3. Mr. C. A. AYiLSOX then read some extracts from A. E. 

 "Wallace's " Geographical Distribution of Animals," and from 

 Tarious papers, in which it was shown that our knowledge of 

 insects and their numbers and varieties, although far in advance 

 of that of a century ago, is far from being complete, and that 

 entomologists nowadays are more dubious about the number o£ 

 varieties than they were in the earlier days ; but they estimate 

 the number at " probably" 300,000 species. He remarked that 

 he had taken a metallic blue butterfly many years ago, of which 

 he had not seen a sjDecimen since. He concluded by giving 

 several interesting particulars regarding South Australian 

 insects, which, however, have at various times appeared in 

 print. 



Oedixart Meetixg, July 5, 1881. 

 His Honor Chief Justice Way, President, in the chair. 

 The list of donations to the Library was read. 

 Mr. E. Meyrick, M.A., Sydney, was elected a Eellow. 



I^OTES AXD EXHIBITS. 



Mr. F. G. Wateehouse, on behalf of the Governors of the 

 South Australian Institute, exhibited a number of specimens 

 of malachite from the Burra Burra Mine, and portion of a 

 very large collection of copper ores lately presented to the 

 Soiith Australian Museum by Sir Henry Ayers. 



The Seceetaey read a report from the Hydraulic Engineer's 

 Department of the results of boring at Stirling North, near 

 Port Augusta. It was stated that a dtpth of 407 feet below 

 the surface had been reached. [The publication of details of 

 this boring is deferred until the completion of the work.] 



Professor Tate made some remarks about a fossiliferous 

 limestone rock found in a well at Mitcham by Mr. AVilcox. 

 He said it left no doubt that there were beds of the Miocene 

 period preserved in this locality beneath the Pliocene Drift. 

 He also referred to a fine crystal of rutile embedded in granite 

 obtained from near Encounter Bay, and exhibited by Mr. T. 

 D. Smeaton. 



The following papers were read : — 



1. " The Geologv of the Neighbourhood of Port Wakefield," 

 by Prof. E. Tate, E.G.S. (see p. 45.) 



