342 E. T. Newton— On " Tasmanite " and "White Coal." 



their ages in relation to each other, and to geological changes and 

 epochs generally." 



The changes in the physical condition of the land necessary for 

 deposition of several alternations of beds of clays and schists, some 

 of which are of considerable thickness, and the subsequent elevation 

 of the whole to 100 feet above the level of the river, show that 

 these Tasmanite schists cannot be of very recent origin, although the 

 distinct and unaltered appearance of the spores might have led one to 

 suppose that they were. The alternations of ]ayers of the schist with 

 beds of laminated clay rock, and the presence of masses of fossiliferous 

 rocks below this series, are extremely suggestive, on account of their 

 resemblance to the succession of strata in the Carboniferous Epoch ; 

 indeed, it seems highly probable, from Mr. Milligan's observations, 

 that these beds of Tasmanite were deposited under conditions very 

 similar to those under which Coal is now generally considered to 

 have been deposited. 



I have at present been unable to ascertain under what conditions 

 the Australian White Coal occurs ; its great resemblance to Tasmanite 

 renders it highly probable that it occurs under very similar conditions. 



The foregoing consideration regarding the composition, microscopic 

 structure, and mode of occurrence of Tasmanite, must, I think, lead 

 to the conclusion, that this deposit is a bed of coal in process of 

 formation ; very inferior coal no doubt, on account of the large 

 admixture of sand and clay, but nevertheless of such a character that 

 it would be considered a true coal. The study of Tasmanite will, 

 I think, enable us better to understand the appearances presented by 

 certain coals : and certainly not the least important fact to be noticed 

 is, that the combustible portion of this deposit, which is closely 

 allied to coal, several feet in thickness and miles in extent, is formed 

 entirely of spores. 



EXPLANATION OF PLATE X. 



Fig. 1. — Section of Tasmanite, cut perpendicular to the plane of bedding, x 50 

 diameters. In the upper two-thirds of the figure the spores are further apart 

 than is usually the case ; in the lower third they are very numerous and more 

 compressed. 



Fig. 2. — A large spore of Tasmanites punetatus which has been ruptured, x 50 

 diameters : snowing the double contour and dotted surface. 



Fig. 3. — A similar but smaller spore, with air in the interior ; x 50 diameters. 



Fig. 4. — Transverse section of a spore, the walls of which have been pressed to- 

 gether from the same section as Fig. 1 ; x 50 diameters. 



Fig. 5. — Portion of Fig. 4, x 250 diameters, to show the perpendicular lines and 

 laminated structure. 



Fig. 6. — Spore filled with black material x "50 diameters. 



Fig. 7.— Portion of similar spore x 250 diameters, shows three of the minute 

 rounded bodies separated from the mass. 



Fig. 8. — Spore of T. punetatus, from the Australian White Coal, x 50 diameters. 



Fig. 9. — Portion of Fig. 8, x 250 diameters, to show the dots and extremely fine 

 granulation of the intermediate portions of the surface. 



Fig. 10. — Section of Better Bed Coal, cutperpendicular to the bedding, x 25 diameters. 

 The large sac-like bodies are macrospores [Fleming ites) ; the intermediate 

 granular-looking portion is composed of microspores and a black material, 

 probably mineral charcoal. 



Fig. 11. — Section of same coal cut in the plane of the bedding, x 150 diameters. 

 Small portion of intermediate part, with microspores. 



