4 B. Henry Walcott : 



yet supplied eridence of a sufficiently definite nature to prove that, 

 the tufi emanated from it. Mahony and Grayson^ say that tuff was- 

 proved in wells sunk through the basalt to the north of the Mount, 

 and they verbaly informed the writer that there was also evidence- 

 of tuff underlying the lavas in other directions. 



This merely introduces the possibility of Mount Noorat having 

 contributed to the Pejark tuff, but one of the other suggested places 

 of origin is accompanied by evidence quite sound enough to fix it 

 as the main source. 



Lakes Keilambete and Terang, although surrounded by accumu- 

 lations of tuff, have not been generally accepted as the sites of old 

 volcanic vents. 



Mr. A. R. C. Selwyn^ thought they were more probably acci- 

 dental depressions due to other causes, and Professor J. W. 

 Gregoryio is confident that they, as well as Lakes Bullemerri and 

 Gnotuk, are not crater lakes, but occupy basins formed by sub- 

 sidences in bedded volcanic tuff, which w^ere probably caused by the 

 eruptions of neighbouring volcanoes. 



Mahony and Grayson, ^i on the other hand, hold that all these 

 lakes are directly due to volcanic explosions, and with this view 

 the writer is in accord. Their paper is a most valuable one, not 

 only on account of the interesting matter it contains, but also be- 

 cause it is the only systematic account of the geology of the district 

 yet published. As these notes must necessarily be brief, and only 

 of a general nature, reference should be made to thai:' paper. 



The part of Lake Keilambete visited by the writer, like nearly 

 the whole of its banks, was hidden by a luxurious growth of grass, 

 with the exception of some outcrops of soft, tertiary, fossiliferous 

 limestone underlying the superficial tuffs. ^2 



8. Loc. supra cit., p. 6. 



9. Intercolonial Exhibition Essays, Melb., 1866. 



10. The Geography of Victoria, Melb., 1903, p. 130. Revised Ed., 1913, pp. 

 131-136. 



11. L.OC. supra cit., p. 13. 



12. Mr. F. Chapman, Palaeontologist to the National Museum, who was good 

 enough to examine all the fossiliferous material collected, determined 

 the Lake Keilambete forms from the limestone as follows : — 



Foramnifera. — Trnncatulina lobatula, W. and J. sp. Also others 

 indet. 



Polyzoa. — Indet. 



Echinidermata. — Echinocyamns (ScutelUna) patella, Tate sp, 

 Eupatagus (?) laubel, Duncan. 



Brachiopoda. — Magellania insolita, Tate sp., and M. (?) pectoralis 

 Tate sp. 



Pelecypoda. — Pecten yahliensis, Tate. 



Pisces. — Lamna apiculata, Ag. sp. 



Mr. Chapman places the limestone bed in the Janjukian series. 

 Oyster shells of fossilized appearance occur on the beach of the lake, 

 and it may be useful to record the fact here given to the writer by 

 Mr. H. Quiney, of Mortlake. that many years ago an attempt was made 

 to acclimatize oysters in the lake, but without success. It is to this; 

 source that the presence of the shells may be attributed. 



