1078 



NOTES AND EXHIBITS. 



Mr. Skuse exhibited a box of specimens illustrating ahnost the 

 whole life-history of the new Dipterous insect referred to in 

 his Note. 



Mr. Ogilby exhibited Tripterygium anmdatuin and Congro- 

 murcena longicathda, as described in his paper. Also, Hoplo- 

 cephalus ortiatus (I) from the Macquarie Iliver, and Pseudechis 

 australis, a species mainly confined to the plains of the west. 



Mr. Fletcher exhibited, for Mr. De Vis, left ramus of lower jaw 

 of Nototherium, n. sp., exhibiting 3rd molar unworn, and the 

 premolar vei'y little abraded. 



Mr. T. W. Edgeworth David, B.A., F.G.S., exhibited specimens 

 of rocks and I'ock-sections, and in reference to them read the 

 following notes : — 



(1) On the occurrence of Basalt-glass (Tachylyte) in the Vege- 

 table Creek district, New England : — 



No previous mention has been made, as far as the author is 

 aware, with the exception of two brief notices made by him in 

 1886, *t of the occurrence of tachylyte in New South Wales. In 

 the present note the author does not attempt to do more than 

 describe the general characteristics of this rock, a detailed account 

 of which he hopes to give on a future occasion. 



The basalt-glasses [tachylytes] hitherto described from other 

 countries are stated to occur chiefly in the following manner : — 



1 (1) As thin, vitreous selvages of dykes, 



(2) As thin coatings on the under surfaces of lava streams. 



(3) As thin crusts on the upper surfaces of basaltic lavas. 



(4) (a) As ejected blocks | lapilli etc.]. 

 (b) As kernels in basaltic tuffs. 



* Transactions of the Geological Society of Australasia, Vol. I. part 1, 

 p. 30. 



t Geology of the Vegetable Ci"eek Tin-miiiing Field, published at the 

 Government Pz'iuting Office for the Department of Mines, Sydney, pp. 28, 

 30 and 31. 



t Quart. Jouni. Geol. Soc. Vol. XXXIX. p. 447. 



