tHE VICTORIAN NATURALIST. 93 



Ripon and Grenville ; on the east it is flanked or underlain by 

 the amphibolites, diabases, epidiorite, and granodiorite * of 

 Batesford and Geelong, Ordovician sediments of the Steightz 

 district, Jurassic sediments of the Barrabool Hills, basalt, of 

 probably early Eocene age, and Cainozoic sediments of the 

 Dean's Marsh district, and the Moorabool and Leigh valleys. 



This Upper Volcanic area, of probably late Pliocene age, or 

 perhaps even younger, is not limited on the east by the rock 

 masses specified, for it extends to the Melbourne district ; and in 

 the intervening area the Older Cainozoic sediments underlie, as 

 has been proved by bores and shafts sunk at Newport and Altona, 

 near Williamstown, and near Laverton and Werribee. 



On the south the Otway Jurassic wedge extends to the coast, 

 forming high, bold cliffs. It is flanked on all sides, though not 

 continuously, with Cainozoic sediments, probably of the older 

 series, wliile a great mass of Older Cainozoic sediments extends 

 along the coast to Warrnambool, narrowing rapidly at the surface 

 from east to west. 



These Cainozoics consist in the main of rather incoherent 

 quartz sands, under which, in the western portion, lie white and 

 yellow limestones of friable and fairly compact texture, together 

 with calcareous clays. These are seen to great advantage in tlie 

 coastal cliffs from near the mouth of the Gellibrand River to near 

 Warrnambool, and again in the basin of Curdie's River. The 

 clays contain a rich fauna, chiefly MoUusca, while the limestones, 

 though also originally rich, have now only the remains of the 

 organisms whose shells consist of calcite, those of aragonite 

 having been dissolved, and casts only left. 



Within this volcanic area of the Western district only a few 

 outcrops of rock other than volcanic occur. The most important 

 of these is between Lakes Bullenmerri and Gnotuk, near Camper- 

 down. This is a deposit of limestone and calcareous clay of 

 Older Cainozoic age, describedt by the late Professor Tate, F.G.S., 

 and Mr. J. Dennant, F.G S., F.C.S., and contains a fauna 

 represented by upwards of loo species. 



The locality from which the fossils recorded herein were 

 obtained is near Hexham, on the Hopkins River, near Muston's 

 Creek junction. It lies near the N.E. corner of the parish of 

 Yeth Youang, and the S.E. portion of Hexham West. A small, 

 narrow strip of Older Cainozoic deposits is marked on the new 

 geological map of Victoria as extending for about 3 miles 

 along the Hopkins River, but I am unable to say of what it 

 consists. 



* These rocks have been determined by Professor Gregory, D.Sc, F.R.S., 

 see "The Heathcotian — a Pre-Ordovician Series, and its Distribution in Vic- 

 toria." (Proc. Roy. Soc. Vic, vol. xv. (N.S.), part ii.,1903, pp. 165, 166.) 



+ " Correlation of the Marine Tertiaries of Australia," part i. (Trans. 

 Roy. Soc. S. Aus., 1893. 



