1857.] SMYTH EXTINCT VOLCANOS OF VICTORIA. 227 



The author regrets that it has not been in his power to extend 

 these comparisons to the rocks of the Vosges on the opposite side of 

 the Rhine valley. He hopes, however, that, unless anticipated, he 

 may have the wished-for opportunity. 



2. On the Extinct Volcanos of Victoria, Australia. 

 By R. Brotjgh Smyth, C.E., F.G.S., Member of Council of the 

 Philosophical Institute of Victoria, &c. 



The district within which volcanic products and other evidences of 

 recent igneous action are found extends from the River Plenty (a 

 tributary of the Yarra), on the east, to Mount Gambier on the west. 

 Its most northern point is McNeil's Creek (a tributary of the River 

 Loddon), in 37° south latitude, and its most southern Belfast, in 

 38° 21' south latitude (see accompanying Map, fig. 1). Its extreme 

 length is 250 miles, and its extreme breadth about 90 miles. 



It is said that there are crateriform hills near Lake Omeo, on the 

 flanks of the Australian Alps, and at Lake Tyrrell, near Castle Don- 

 nington, on the River Murray ; but I have not such precise informa- 

 tion as would warrant me to mark those as belonging to or connected 

 with the district now under consideration. 



By referring to the map it will be seen that this district is bounded 

 on the south by the sea, and on the north it crosses the Spur from 

 the Australian Alps near the Ballaarat Gold-fields * . In the centre 

 is a basin-like depression, the drainage of which is into Lake Ko- 

 rangamite. 



The most distinctly marked crateriform volcanic hills are : 



1 . A hill near the source of the Merri Creek, on the dividing range, 

 about 25 miles north of Melbourne. Respecting this, Mr. Selwyn, 

 the Government Geologist, says : — " On the green hill north of the 

 Kinlochue Inn, Sydney Road, the ancient crater is still distinctly 

 visible. Several other and smaller hills of the same character, but 

 on which no crateriform cavities are visible, occur near the source 

 of the Merri Creek ; and there is little doubt that these hills are the 

 true source whence the whole of the basalt or lava which now occu- 

 pies the country between the Plenty, the Yarra, and the Sydney- 

 Road has been derived." And on referring to his recent map of 

 that part of the country, I perceive that, in cutting a roadway, vol- 

 canic ash and scoriae were found. The altitude of this hill is about 

 700 feet. 



2. Mount Aitkin. — This hill is about 1500 feet above the level 

 of the sea. There is no deep well or crater, but the evidences of 

 recent volcanic action are complete and satisfactory. The summit 

 is covered with masses of naked basalt extending in two parallel 

 ridges ; and the course of the streams of lava may be traced from 

 the hill. The surface is strewn with fragments of light vesicular 

 lava. The basalt at the summit is not dissimilar to the rock which 



* See Quart. Journ. Geol. Soc. vol. ix. p. 75, and ' The Golden Colony,' 1855, 

 chap. 16, for Mr. Wathen's account of a portion of this volcanic district. — Edit. 



