IX] SCHIZONEURA. 291 



Jurassic and Upper Palaeozoic rocks in Australia. Some of 

 these possess cup-like leaf-sheaths, and in the case of the thicker 

 specimens they show continuous ridges and grooves on the 

 internodes, as well as a habit of branching similar to that in 

 some of the Italian Phyllothecas. In some of the stems it is 

 however difficult to recognise any characters which justify the 

 use of the term Phyllotheca. A fragment figured by Tenison- 

 Woods^ as a new species of Phyllotheca, P, carnosa, from Ipswich, 

 Queensland, affords an example of the worthless material on 

 which species have not infrequently been founded. The author 

 of the species describes his single specimen as a " faint im- 

 pression"; the figure accompanying his description suggests 

 a fragment of some coniferous branch, as Feistmantel has 

 pointed out in his monograph on Australian plants. 



It is important that a thorough comparative examination 

 should be made of the various fossil Phyllothecas with a view 

 to determine their scientific value, and to discover how far the 

 separation of Phyllotheca and Equisetites is legitimate in each 

 case. There is too often a tendency to allow geographical 

 distribution to decide the adoption of a particular generic name, 

 and this seems to have been especially the case as regards 

 several Mesozoic and Palaeozoic Southern Hemisphere plants. 



The geological and geographical range of Phyllotheca is a 

 question of considerable interest, but as already pointed out it 

 is desirable to carefully examine the various records of the 

 genus before attempting to generalise as to the range of the 

 species. Phyllotheca is often spoken of as a characteristic 

 member of the Glossopteris Flora of the Southern Hemisphere, 

 and its geological age is usually considered to be Mesozoic 

 rather than Palaeozoic. 



III. Schizoneura. 



The plants included under this genus were originally 

 designated by Brongniart' Convallarites and classed as Mono- 

 cotyledons. Some years later Schimper and Mougeot' had 



> Tenison -Woods (83) PI. ix. fig. 2. « Brongnlart (28) p. 128. 



'•* Schimper and Mougeot (44) p. 48, Pis. xxiv— xxvi. 



19—2 



