10 THE TWO FLORAS [ch. 



Archaeopteris Flora , Psilophyton Flora 



Hyenia, Sphenopsida Psilophyton . 



Psygmpphyllum, Palaeophyllales Broggeria 



§ Thursophyton 





Pseudosporochnus 



g ° Sphenopieridium, Pteropsida Hostimella 



S g Barrandeina 



Archaeosigillaria \ 



Leptophloeum > Lycopsida 



Protolepidodendron I 



1 Leptophloeum, Lycopsida Psilophyton 



y 5 Arthrostigma 



g g Parka 



o ° Hostimella 



P (Crypioscylon) 



We now propose to review the distribution of the above genera 

 in the standard Devonian floras indicated in Chapter I. 



Scotland. 



A revised Summary of the Devonian Flora of Scotland^ occurring 

 in the Old Red Sandstone with the dates of their first record 

 from Scotland. 



Upper Old Red Sandstone (Caithness)^ : 



Ptilophyton Thomsoni, Dawson^, 1878 (includ. Caulopteris 

 Peachii, Salter^ 1859). 



Thursophyton Milleri, (Salter)', 1858. 



T. Reidi, (Penhallow) \ 1892. 



Archaeopteris hibernica, (Forbes)', 1857. 

 Middle Old Red Sandstone (Cromarty)*: 



Psilophyton princeps, Dawson', 1841. 



^ This list chieily differs from that given by Kidston in 1902 (Kidston 

 (1902)) in regard to the horizons to which the fossils are ascribed, which 

 we have given in accordance with the conclusions of the Scottish Geological 

 Survey. ^ Crampton and Carruthers (1914). 



3 Carruthers (1873), PI. 137; Dawson (1878), p. 385 and PI. IV. 



* Salter (1859), p. 408, Fig. 14a. 



5 Salter (1858), p. 75; Penhallow (1892), p. 5; Nathorst (1915), p. 17. 



8 Penhallow (1892), p. 8, PI. I, fig. 2; Reid and Macnair (1899), PI. XXII; 

 Nathorst (1915), p. 19. 



' Miller (1857), p. 454, Fig. 124. » Home and Hinxman (1914). 



9 Miller (1841), p. 100, PI. VII, figs. 8-5; Miller (1857), Fig. 119, p. 429, 

 Fig. 120, p. 432; Dawson (1859), p. 481. 



