TASMANITES 



17 



with a different microfossil assemblage. 

 Some of Singh's specimens without doubt 

 are bonafide plant spores. However, he 

 found many forms with about the same 

 shape and size proportions as T. punctatus 

 but was unable to see any of the punctae. 

 Trilete markings were clearly visible in 

 some but for others he suggests they 

 ''seem to have been rubbed off during 

 fossilization." This, of course, seems 

 quite improbable since the trilete suture 

 lines, if present, cannot be removed by 

 fossilization. Of the figures presented by 

 Singh, actually only one (fig. 3) shows 

 convincing evidence of the trilete mark- 

 ing. The proportions of this specimen 

 suggest Calamospora and it is interesting 

 to note that Phyllotheca (a calamarian) 

 is associated in the same strata. Those 

 shown in his figures 7 and 8 are incon- 

 clusive as to the presence of a trilete 

 structure, since Tasmanites may occasion- 

 ally be folded under compression to simu- 

 late a trilete marking ; but careful observa- 

 tion will distinguish the absence of a 

 definite suture line. Since Singh has 

 not shown these structures, actually the 

 only great discrepancy between Newton's 

 and Singh's observations with respect to 

 the more common forms concerns the 

 punctae. 



American Tasmanites forms show con- 

 siderable variation in the frequency of 

 punctae and this may be a useful means 

 of specific discrimination. One can 

 scarcely doubt their existence in Newton's 

 original material, because Reinsch also 

 figured them from the Tasmanite mate- 

 rial provided from the British Museum 

 and also used and figured additional speci- 

 mens from Newton's own preparations. 

 So far as tlie discrepancy in presence of 

 a trilete mark on some specimens is con- 

 cerned, it must be noted that Reinsch (II, 

 1884, p. 5) also found "Rarissime oc- 

 current Triletes minores singuli inter- 

 spersi" in Newton's original material. 

 Furthermore, the way Newton's descrip- 

 tion in general tallies with the verified 

 characters seen in American Tasmanites 

 is so striking as to leave no doubt as to 

 the essential correctness of his description. 



The surprising thing about American 

 assemblages containing Tasmanites is that, 

 so far as is known to be true, no trilete 

 forms (excepting Foerstia) have yet been 

 found to occur with them in the assem- 



blage. That Reinsch and Singh have 

 found a few trilete spores associated 

 with Tasmanites is not to be wondered 

 at. The writers are convinced that, de- 

 spite assocations of this sort, Tasmanites 

 does not now, and never has had, any 

 trilete marking on its wall. Lack of this 

 feature is conclusive evidence that Tas- 

 manites does not represent any group of 

 ordinary pteridophytic plants. 



Discussion. — There are many spor- 

 angite forms which do not qualify as 

 species of Tasm^anites, or any other genus 

 yet designated. Aside from Lang's paper 

 there has been no attempt to report on 

 isolated actual bonafide plant microfossils 

 of similar age. Until more reports are 

 available and greater knowledge has been 

 obtained, it does not seem essential to 

 give further taxonomic consideration to 

 the few that are known. The correlation 

 and coordination of taxonomic groups 

 identified by means of spores from the 

 Devonian, with those groups based on 

 spores which we are utilizing for Carbo- 

 niferous material, deserves very thorough 

 study and consideration. The abundant 

 plant record that can be obtained may, if 

 advisedly interpreted, have much sig- 

 nificance in tracing lines of phyletic rela- 

 tionship among plants. The results that 

 may possibly accrue from study of the 

 problematic microfossils, among which is 

 Tasmanites, is hard to predict, although 

 such study cannot fail to at least outline 

 their stratigraphic usefulness. 



It needs to be stressed, however, that 

 Tasmanites, and other unicentric micro- 

 fossils certainly do not belong to the well 

 known groups of primitive higher plants 

 that were contemporaneous with them. 

 Their morphologic nature is, in fact, so 

 uncertain that their reference to the plant 

 kingdom would not seem assured except 

 for their chemical composition. Zetzche, 

 et al., (1931) seem to have definitely 

 proved the absence of nitrogen from 

 authentic Tasmanites and furthermore 

 shown their composition to be in general 

 similar to unquestioned fossil plant spores. 

 Though possibly chitinous in appearance, 

 lack of nitrogen apparently eliminates 

 the animal kingdom from consideration. 

 Spores of Parka which evidently is a 

 thalloid plant, evidently lack any hapto- 

 typic structures (Don and Hickling, 

 1915) but in no other particular do 



