32 



THE PSILOPHYTON FLORA 



[CH. 



Ptilophyton. 

 (Figs. 12-14.) 



Ptilophyton, Dawson^, 

 1878. Main axis (Fig. 12, 

 p. 31) very stout, striated, 

 (the Caulopteris 1 Peachii 

 of Salter^; of. also the 

 genus Barrandeina) giving 

 off stout lateral decurrent 

 shoots almost at right 

 angles. Branches covered 

 with scale-like emergences. 

 At the apex the axis is 

 freely and closely alternate- 

 ly branched, producing a 

 tuft of shoots*, the ends of 

 which are circinately coiled 

 (Fig. 13). The ramij&cations 

 of this tuft bear, apparently 

 on one side, a row of long 

 thin (?fil9,mentous) obscure 

 organs, the nature of which 

 is unknown. They have 

 been described as " tufts of 

 linear bodies*." 



Distribution. Middle De- 

 vonian, ? Bohemia; Upper 

 Old Red, Scotland. 



This genus, markedly 

 different from Psilophyton 

 in habit, is still entirely ob- 

 scure. We may note how- 

 ever that what is probably 



1 Dawson (1878). 



2 Salter (1859), p. 407, Fig. 14 

 on p. 408; Kidston (1902) de- 

 finitely states that Caulopteris 

 Peachii, Salter, is the stem of 

 Ptilophyton Thomsoni, Dawson. 



3 Carruthers (1873), PI. 137. 



Fig. 13. Ptilophyton Thomsoni, Dawson. 

 The terminal portions of axes possessing 

 emergences. Type specimen from the 

 Upper Old Red of Scotland. (Reduced 

 about f.) After Carruthers (1873). 



