BY T. W. EDGEWORTH DAVID. 493 



Dr. Seeman as a jelly-like mass several feet thick, with a tall 

 species of sedge growing in it. The following analysis made by 

 Dr. Bernays discountenances, however, this theory entirely. 



He found : 



Moisture -4682 



Carbon 64-7300 



Hydrogen 11-6300 



Ash 1-7900 



Oxygen and unestimated matters.... 20-3768 



Any residue left by a Cryptogam (assuming, of course, that no 

 extensive change of composition had taken place in it, except the 

 loss of watei) would contain about 50 per cent, oxygen, or far more 

 than the ivhoh of the unestimated matter put down above ; it 

 would also contain much less hydrogen. It may, therefore, be 

 safely concluded that no cryptogamic growth could have produced 

 a substance which is practically a hydro-carbon and not a carbo- 

 hydrate." 



Professor Thiselton Dyer concludes that coorongite may be 

 the oozing or secretion of some plant like the grass-tree f Xan- 

 thorrhcEa) or it may have been formed from petroleoid springs. 

 The diatoms found in the coorongite are all freshwater species, as 

 the author is informed by Mr. J. J. Fletcher, M.A., B.Sc, to 

 whom he is indebted for the above reference to Professor Thiselton 

 Dyer's paper, and also for the following reference to a description 

 of the diatoms associated with coorongite."^ 



Mr. R. Etheridge, jun., has also kindly supplied the author with 

 the following references to coorongite. f 



* Quarterly Journal of Microscopical Science. Vol. XIII. New Series, 

 p. 211. " The diatoms in the Australian Caoutchouc, &c," by the Rev. E. 

 O'Meara. 



t Coorongit, a New Australian Mineral Product. Baird's Annual Record 

 of Science and Industry for 1872, p. 134. 



Coorongit. Das Australische Kautschuk Coorongit. Der Naturforscher, 

 1872, V. No. 23, p. 186. 



