THE VICTOIUAN NATUKALIST. 221 



rhombic j)rism witli orthopinacoid, clinopinacoid, ortliodome, 

 and basal planes, and their habit is a broad development parallel 

 to the clinopinacoid, and rather narrow parallel to the 

 orthopinacoid. The largest crystal measured in situ was 4 inches 

 in length, but 2 5^ to 3 inches was more about the average size of 

 the large crystals. Another very remarkable example of rock 

 weathering is shown in this same locality, where the rock appears 

 at first sight like a heavy conglomerate, with large pebbles sticking 

 out of it, owing to the removal of the matrix. The rock is not so 

 coarse as that just mentioned above, but when in its original 

 molten state it included masses of other material of apparently a 

 more basic character, and these are the rounded and irregularly 

 disposed, fine-grained, dark-greyish lumps that appear like 

 pebbles, owing to the faster weathering of the granitic matrix. 



Both black and white micas, apparently Biotite and Muscovite, 

 are abundantly distributed through the rock, but none was seen of 

 any size. 



To the south of Oberon Bay, the medium-grained granite was 

 also garnetiferous, the species represented being Almandite. 

 Washings from granitic detritus at Yanakie landing are recorded 

 to have yielded zircons, sapphires, and topaz, but we did not 

 procure any along our route. Most of the exposed hills and 

 points jutting into the sea appear pretty bare of vegetation until 

 one tries to climb up ; then they are covered with a mass of 

 matted vegetation which it is easier to walk over than to force a 

 passage through, as the various plants are beaten down flat by the 

 strong winds. Where the granite is usually bare of vegetation is 

 only on the steepest and most inaccessible slopes, and on the 

 tors, but even the latter show evidence in places of the inroads 

 caused by plant growth. On other parts the granite carries 

 heavy timber, and in places much undergrowth. In some of the 

 valleys there is good drainage, and splendid water runs down to 

 the sea at frequent intervals ; but in some there is no longer fall 

 for the water to get away, and the development of swamps and 

 morasses is a consequence, as up the Tidal River, and on the 

 way to Waterloo Bay, and other places. These deposits can 

 only be regarded as a recent development from the granitic 

 detritus. 



Silurian. — There is none of this rock on the lower part of the 

 promontory itself, but around Foster it is frequent enough, and 

 extends over to the northern slopes of the Hoddle range. A 

 junction of this rock with the granitic rock of the Promontory is 

 recorded on the Corner Basin coast, near Yanakie, which shows 

 the granite to be of younger age than the Silurian. 



At Foster the rocks are mudstones, shales, and sandstones, 

 very similar in lithological character to the rocks round Mel- 

 bourne, such as at Diamond Creek. From the mullock heap of 

 the mine at Foster a hard, close-grained, yellowish-grey rock con- 



