During Triassic and Jurassic Periods 185 



strata from America through Europe to Africa, India, and 

 Australia. 



As being of great importance from the physico-bio- 

 logical standpoint, Hatch and Corstorphine point out that 

 on top of the Stormberg beds, though doubtfully at what 

 particular time, great deposits of volcanic material were 

 thrown out, which in some places have a thickness of 4500 

 feet. Such enormous volcanic deposits must have caused 

 and accompanied tremendous alterations in land-areas, 

 wide-spread destruction to plant and animal life, constant 

 oscillations in land and water surfaces, as well as other 

 environal changes that would all aid in the evolution of new 

 species and genera, as well as the obliteration of others. 



Neglecting Indian strata, that promise greatly more 

 for the future than the secured results indicate, attention 

 may now be given to Australian Triassic developments. 

 As set forth by Freeh these extend through Queensland, 

 Victoria and New South Wales, on even to the Island of 

 Tasmania, and are mainly if not wholly of freshwater 

 origin. Thanks to the efforts of A. S. Woodward, the fish- 

 fauna has received considerable attention {141 '. 10). The 

 general nature of the flora and fauna has been treated by 

 Etheridge and Feistmantel, who observe that plants and 

 fish are plentiful. Estheria coglani, as a native phyllopod, 

 persists through hundreds of feet of strata, while the two 

 labyrinthodonts Mastodonsaurus and Platyceps are associ- 

 ated. Feistmantel has given (7^2:40) a classified list of 

 the organisms found up to about 1890. 



In Woodward's earlier communication on fishes from 

 Gosford rocks, Edgeworth David makes a preliminary 

 statement, in part as follows : "Although the shales as- 

 sociated with the fish-beds are probably partly tufaceous, 

 it is very improbable, to judge from the remarkable even- 

 ness and regularity of these strata, that the fish perished 

 through an inflow of volcanic mud, or the falling of a 

 shower of volcanic dust. The evidence quoted seems rather 

 to favor the supposition that the fish, which evidently lived 

 in some land-locked lake or sheltered estuary, where there 

 was not suflicient current to efface the ripple marks, and 



