76 LYCOPODIALES [CH. 



specimen of the latter species bears a label describing it as 

 Lycopodium arhoreum (Sir Joseph Hooker and Dr Solander ; 

 1769). The twigs of the Tasmanian conifer Microcachyrs 

 tetragona Hook. f. are very similar in habit to shoots of the 

 recent Lycopodium tetragonum (fig. 121, C). 



In the description of examples of Lycopodites and Selaginel- 

 lites I have confined myself to such as appear to be above 

 suspicion either because of the presence of spore-bearing organs 

 or, in a few cases, because the specimens of sterile shoots are 

 sufficiently large to show the form of branching in addition to 

 the texture of the leaves. The two generic names Lycopodites 

 and Selaginellites are employed for fossil species which there 

 are substantial grounds for regarding as representatives of 

 Lycopodium and Selaginella. The designation Selaginellites is 

 adopted only for species which afford evidence of heterospory ; 

 the name Lycopodites, on the other hand, is used in a comprehen- 

 sive sense to include all forms — whether homophyllous or hetero- 

 phyllous — which are not known to be heterosporous. This 

 restricted use of the generic name Selaginellites is advocated 

 by Zeiller^ who instituted the genus, and by Halle ^ in his 

 recent paper on herbaceous lycopods. 



Lycopodites. 



The generic term Lycopodites was used by Brongniart in 

 1822* in describing some Tertiary examples of slender axes 

 clothed with small scale-like leaves which he named Lycopodites 

 squamatus. These are fragments of coniferous shoots. In the 

 Prodrome d'une histoire des vdgetaux fossiles^ Brongniart 

 included several Palaeozoic and Jurassic species in Lycopodites 

 and instituted a new genus Selaginites, expressing a doubt as to 

 the wisdom of attempting to draw a generic distinction between 

 the two sets of species. In a later work* he recognised only one 

 undoubted species, Lycopodites falcatus. The first satisfactory 

 account of fossils referred to Lycopodites is by Goldenberg^ 



1 Zeiller (06) p. 140. a Halle (07). 



•* Brongniart (22) A. p. 304, PI. vi, fig. 1. * Brongniart (28) A. p. 83. 



6 Brongniart (49) A. p. 40. « Goldenberg (55) p. 9. 



