340 E. T. Newton— On « Tasmanite" and "White Coal." 



Nearly all the sacs are so compressed that their walls are brought 

 into contact ; but occasionally one may be found similar to Fig. 6, 

 containing a quantity of black material differing in appearance from 

 the surrounding matrix, and which appears to consist of minute 

 rounded particles, about -^-^-^ of an inch in diameter. 



With regard to the affinities of the discs, or rather sacs, it must be 

 acknowledged that their true nature has yet to be determined. Their 

 general structure seems to indicate that they are the spores or 

 sporangia of some Lyeopodiaceous plant ; but their true affinities 

 must remain obscure until they are found in their natural relation to 

 the parent plant, or some recent form is discovered with which they 

 can be compared. By the kindly help of Mr. Carruthers, I have been 

 enabled to examine the fructification of several recent forms, but 

 have failed to find anything comparable in structure to these sacs. 

 Prof. Balfour, I believe, considers the Tasmanite discs to be closely 

 allied to Flemingites ; they differ from them, however, as Mr. 

 Carruthers has pointed out (Geol. Mag. 1865), both in structure and 

 size. All the Flemingites macrospores which I have seen have 

 homogeneous walls, and in many of them is seen the triradiate 

 marking, which is so generally present in cryptogamic spores (Prof.' 

 Williamson, Macmillan's Mag. March, 1874, p. 409). In none of the 

 Tasmanite sacs have I been able to see this triradiate marking, 

 although their structures are so clearly shown that these markings 

 could not fail to be seen if they were present ; and the walls, as we 

 have already seen, have a definite structure. The sporangia of 

 Lepidostrobus figured by Dr. Hooker (Mem. Geol. Survey, 1848, vol. 

 ii. part ii. pi. 6, figs. 4, 10, and pi. 7, fig. 7) have somewhat the same 

 appearance as the transverse sections of Tasmanite sacs, that is to 

 say, they show a series of lines perpendicular to the surface. A 

 closer examination, however, of the figure, or, still better, of the 

 original specimens, shows that the two structures are not the same. 

 In the Lepidostrobus sporangia the lines are really the walls of the 

 cells of which the sporangia are composed. In the Tasmanite sacs 

 the lines have quite a different appearance, and a surface view shows 

 that they are not merely the lines of junction between cells. 



The minute black bodies mentioned above as filling the cavities of 

 some of the discs are very much smaller than any of the microspores 

 mentioned by Prof. Williamson (Macmillan's Mag. March, 1874, p. 

 408), and they do not show any cell wall. 



In the abstract of a paper by Mr. Thos. S. Ealph (Trans. Koy. 

 Soc. Victoria, vol. vi. 1865, p. 7), the discs of Tasmanite are referred 

 to Algae. This, I venture to think, is improbable. 



There can be no question as to the Tasmanite sacs being vegetable 

 organs, although at present we do not know the plant to which they 

 belong. Their size and form seem to indicate that they are more 

 nearly allied to Lyeopodiaceous macrospores than to anything else. 



The inconvenience of having an object without a distinctive name 

 induces me to propose one for the spores (?) found in Tasmanite and 

 Australian White Coal (the two being, as I believe, identical in struc-r 

 ture) ; and in order to retain existing titles as far as possible, I would 



