Obsidian Bombs in Austro.lia. 53 



DESCRIPTION OF PLATES. 

 Plate I. 



Fig. 1.— Elongated "obsidianite." Mount Elephant, Victoria. In 

 the Industrial and Technological Museum Collection. 



Fig. 2. — Side view of a specimen similar to Fig. 1. Albany, 

 West Australia. In the Industrial and Technological 

 Museum Collection. 



Fig. 3. — " Obsidianite " of the spherical type. West Australia. 

 In the Industrial and Technological Museum Collec- 

 tion. The reverse side is quite similar to that shown. 



Fig. 4. — Side view of the spherical type. It differs from Fig. 3 

 in having a corrugated side. Locality not known. 

 In the Industrial and Technological Museum Col- 

 lection. 



Fig. 5. — Top view of a specimen similar to Fig. 4, but more 

 flattened. Mount Oxley, New South Wales. In the 

 Industrial and Technological Museum Collection. 



Fig. 6. — " Button-obsidianite," showing a cavity near the centre 

 and three curious radial cracks. Lisle, Tasmania. 

 In the Industrial and Technological Museum Col- 

 lection. 



Fig. 7. — " Button-obsidianite " of very perfect form. Charlotte 

 Waters, Central Australia. 



Fig. 8. — Unique specimen of the elongated type, with rim broken 

 away in part. The under side is quite smooth and 

 lustrous, and bears the flat grooving characteristic of 

 the button type. Back Creek, Tasmania. In the 

 Industrial and Technological Museum Collection. 



Fig. 9. — Rim and solid ellipsoid centre which have become 

 separated. Mount Elephant, Victoria. In the Indus- 

 trial and Technological Museum Collection. 



Plate II. 

 Fig. 1. — Hollow "obsidianite." Upper Regions Station, Hors- 

 ham, Victoria. In the National Museum Collection. 

 Fig. \a. — Section of same, showing the cavity with a high polish. 

 Fig. 2. — Rim and solid centre (Fig. 9, Plate I.) combined. 

 Fig. 3. — Reverse view of Fig 7, Plate I. 



