XIIl] PSILOTITES, ETC. 25 



Schimper' spoke of the specimens as too doubtful for deter- 

 mination, an opinion with which every botanist would cordially 

 agree. Goldenberg's species Psilotites lithanthracis" from 

 the Saarbriicken coal-field is founded on impressions of axes : 

 some of these are dichotomously branched and bear small oval 

 projections, which may be rudimentary leaves or possibly leaf- 

 scars. More recently Kidston^ described specimens of branched 

 axes from the Lanarkshire coal-field bearing a row of lateral 

 thorn-like projections under the title Psilotites unilateralis ; 

 but these fragments, as Dr Kidston himself admits, are of no 

 botanical value. 



In a paper on fossil Salvinias, Hollick^ mentions Salvinia 

 reticulata, originally described by Heer and by Ettingshausen 

 and 8. Alleni Lesq.^ a Tertiary species, and calls attention to 

 their very close resemblance in form, nervation, and apex to the 

 leaves of the genus Tmesipteris : he refers both species to that 

 genus. The drawings reproduced by Hollick represent leaves 

 with a midrib and numerous anastomosing lateral veins, 

 whereas in Tmesipteris the lamina of the leaf has a midrib 

 without lateral branches. An enlarged drawing of the outlines 

 of the epidermal cells would correspond closely with the small 

 reticulations in the fossil leaves and it may be that there has 

 been some confusion between veins and cell-outlines. In any 

 case there would seem to be no reason for the use of the recent 

 generic name®- 



Among other fossils assigned to the Psilotales we have 

 Marion's genus Qomphostrobus from the Permian of France and 

 Germany'. Marion placed this plant in the Coniferales on the 

 strength of its resemblance to Walchia and Araucaria, but 

 Potoni^^ is inclined to recognise in the leaves and monospermic 

 sporophylls characters suggestive of Lycopodiaceous affinity. 



1 Sohimper (70) A. p. 75. ^ Goldenberg (55) p. 13, PI. ii. fig 7. 



3 Kidston (862). 4 Hollick (94) p. 255, figs. 12, 13. 



^ Lesquereux (78) PI. v. fig. 11. 



' Since this was written I have had an opportunity of seeing a leaf labelled 

 Tmesipteris from the Tertiary plant-beds of Florissant in a collection recently 

 acquired by the British Museum -. the specimen bears no resemblance to a leaf 

 of the recent genns. 



' Marion (90). ' Potoni6 (93) A. p. 197, Pis. xxvii., xxviii., xxxin. 



