:')66 Ernest W. Skeats : 



Examination of interior of Avstralite. 



The australite was immersed in water in a watch glass, and 

 examined under the microscope. 



On focusing beneath the surface of the australite, it was 

 noticed that the pits or bubbles were internal, as well as external, 

 and were in places arranged roughly in rings. A few still smaller 

 gas bubbles, with dark borders, were also noticed. The specimen 

 was entirely glassy and isotropic, except for slight evidence of 

 strain polarization. 



Conclusion. 



The three australites above described are remarkable, and I 

 think constitute more or less distinct types from any hitherto 

 described. The best and most complete reproduction of different 

 types of australites is given by Mr. E. J. Dunn,i and includes 

 button shaped, ellipsoidal. dumb-lDell shaped, and almost spherical 

 forms. 



To these must now be added the " pine-seed " type, the " boat- 

 shaped " type, and the discoidal type. 



The three specimens described are remarkable also for their small 

 dimensions and light weight. I believe the disc-shaped specimen 

 from the Stony Creek Basin in the Grampians is the smallest and 

 lightest australite hitherto described. 



DESCRIPTION OF PLATE. 



A is the pine-seed type of australite. (Nat. Miiseum collection). 



B is the disc-shaped type of australite. (Geol. Dept. Univ. collec- 

 tion. 



C is the boat-shaped type of australite. (Geol. Dept. Univ. col- 

 lection. 



Below each australite is a drawing of a transverse section through 

 the australite, and a drawing of the upper surface, showing 

 the flange and peculiar distribution of grooves. Millimetre 

 and inch scales are shown. 



1 Records of Geol. Survey of Victoria, vol. ii., pt. 4, 1908, pp. 202-207 

 r.uUetiii of Geol. Survey of Victoria, No. 27, 1912. 



