42 THE PSILOPHYTON FLORA [CH. 



TAENIOCRADA. 



Taeniocrada, D. White 1 , 1905. This name is applied to a very 

 fragmentary and obscure palmate "frond," deeply dissected 

 into dichotomous lobes, with an indistinct central strand or axis. 

 It is regarded as an "alga" by David White. 



Distribution. Upper Devonian, United States. 



ZOSTEROPHYLLUM. 



(Fig. 22.) 



Zosterophyllum, Penhallow 2 , 1892. Obscure elongate ? axes 

 aggregated in the form of a tuft, arising from a common horizontal 

 ?axis; erect? axes longitudinally finely striated; striations equal, 

 parallel ; axes ? ribbon-like, linear, simple or dichotomously 

 branched. Some of the ? axes bore small, ? lateral, rounded or 

 oval sporangium-like bodies. 



Distribution. Lower Old Red, Scotland. 



This fossil is at present wholly obscure. 



PROTOLEPIDODENDRON. 



Protolepidodendron, Krejci 3 , 1879, Small leafy twigs with 

 small, oval-lanceolate leaves; leafless stems with spirally 

 arranged leaf bases; leaf bases small, fusiform; leaf scar absent 

 or indistinct (? decorticated). 



Distribution. Middle Devonian, Bohemia. 



A very obscure type, P. karlsteini, in Bohemia. 



HOSTIMELLA. 



(Fig. 23.) 



Hostimella, Potonie and Bernard 4 , 1904. Repeatedly bifur- 

 cating slender branch systems without emergences, or other 

 distinctive characters,, though sometimes possessing circulate 

 vernation. Typical example, H. hostimensis, P. & B. var. 

 rhodeaeformis, P. & B. 



1 White (1905). 



2 Penhallow (1892); Reid and Macnair (1899). 



3 Krejci (1879); Potonie and Bernard (1904). 



4 Potonie and Bernard (1904). 



