44 



to have been the centre of very active disturbance. The vege- 

 tation of these regions is distinct in character from the litoral 

 province. The true Tasmanian features are there developed 

 largely, and especially connected with Australia, but having 

 peculiarities of their own. What these peculiarities are I 

 shall refer to presently. It is said that if Australia were sub- 

 merged to the depth of 600 feet it would cover all our marine 

 tertiary rocks, and therefore it is concluded that the Continent 

 has been uplifted something more than that since the later 

 tertiary period. As the same marine beds are found in Tas- 

 mania, it is highly probable that this Island has been separated 

 from Australia since the close of the Mesozoic period. The 

 upheaval of the south coast of Australia has been very general 

 and gradual,and though evidently Tasmania has not participated 

 largely in it, there is enough to prove that it was once a much 

 smaller island, or rather, group of islands, than it is now, and 

 therefore less connected with Australia. When those tertiary 

 rocks, containing shells, were at the bottom of the sea, the 

 ocean must have washed a very considerable portion of the 

 flanks of the mountains, and covered the most of the plains. 

 These plains now unite the mountains into a single island, 

 but then were channels between many large and precipitous 

 islands. It would not be at all difficult to construct a map of 

 the group of islands forming the land of Tasmania. A depres- 

 sion of 300 feet would, perhaps, be sufficient on the northern, 

 and less than that on the southern side. I am not aware if 

 any well defined " desert sandstone" has ever been found in 

 Tasmania, but a priori we should conclude that the formation 

 did not exist. It is supposed to be a limestone and subaeriel 

 deposit, due to the weathering of arenaceous rocks. It includes 

 occasionally drift wood, and rounded quartz pebbles. The 

 conditions of its origin are as yet very obscure. If it be 

 represented at all in this Island, it must be in those heaths or 

 sandy plains whose soil is derived from adjacent granites, such 

 as the coast plains north of Falmouth. 



We find on the east side of Australia, even in the northern 

 portions, very well marked deposits, which tend to show the 

 age of some of the extensive dykes. Thus, at Gympie, a gold 

 diggings, 120 miles north of Brisbane, we have quartz reefs 

 intersecting Diorite, the whole intruding on Devonian rocks, 

 which are much disturbed in consequence. We have here 

 also ash beds or tufaceous rocks which show proximity to the 

 point of ejection. The Devonian fades of the fossils is very 

 decided, the species being identical with European forms. 

 Strophomeiia rhomboidalis,~PhiU.iips,isYery common and this shell 

 occurs on the Silurian Devonian and Carbonferous rocks over 

 large areas of the globe. It has been figured and described by 



