56 



THE ARCHAEOPTERIS FLORA 



[CH. 



mented, nodes curved, irregularly branched. There may be 1-2 

 branches on each node. Leaves shortly stalked, borne in whorls 

 of four at the node, dichotomously divided, margins finely 

 toothed, veins fan-like. Fructification a catkin-like body, up to 

 32 cm. long, with short internodes ; sporophylls whorled, ? forked 

 dichotomously, ? all fertile in the lower parts ; sporangia con- 

 taining megaspores. 



Distribution. Upper Devonian, Bear Island. 



This very interesting type is a now well-acknowledged member 

 of the Sphenopsida. It is a very rare plant. 



Fig. 28. Archaeopteris hibernica, 

 (Forbes), from the Upper Old Red 

 of Kiltorkan, Ireland. (1) Complete 

 frond (greatly reduced). (2) Fertile 

 portion of a frond (much reduced). 

 (3) Sterile pinnules (reduced). After 

 Carruthers (1872). 



PALAEOPHYLLALES l . 



Psygmophyttum, Schimper, 

 1870 (Fig. 27, p. 55). Leaves 

 large, Habellate or cuneiform, 

 arranged spirally on an axis, 

 sheathing at the base, which 

 is fairly broad and not con- 

 tracted to a slender petiole, 

 Apex broad, rounded or trun- 

 cated, entire or lobed, or 

 slightly divided. Nerves flabel- 

 late. Fructification entirely 

 unknown. 



Distribution. ? Lower Devo- 

 nian, Spitzbergen; ? Middle 

 Devonian, Western Norway ; 

 Upper Devonian, Ellesmere- 

 land, Spitzbergen, Canada and 

 United States; Lower and 

 Upper Carboniferous. 



This is a very striking and 

 widely distributed genus in 

 Devonian rocks. A monograph 

 of it was published by the 



1 Arber (1912), p. 405. 



