288 



CONIFERALES INCERTAE SEDIS 



[CH. 



B 



FIG. 747. Gomphostrobus 

 bifidus; a, leaf -scar; b, 

 scar of sporangium?; 

 c, torn piece of tissue. 

 (A, B, after Potonie; 

 C, Zeiller.) 



with two divergent distal prongs varying considerably in the angle 

 of divergence, a variation noticed also by Zeiller. On one example 

 (fig. 747, B) Potonie records the occurrence 

 of two scars ; a lower scar, a, representing 

 the attachment of the lamina and a second 

 scar, 6, which he attributes to a sporan- 

 gium. 



The species, represented usually by de- 

 tached sporophylls only, is recorded from 

 Lodeve, Brive, and other French localities 1 , 

 also from Permian localities in Germany. 

 It was referred by Schenk to Dicrano- 

 phyttum, but in that genus it is the foliage- 

 leaves that are forked and there is no reason 

 to assume any close relationship between 

 the two imperfectly known types. If the scar 

 at the base of the sporophylls marks the position of a seed a com- 

 parison with the Araucarineae is suggested, and in this connexion it 

 is noteworthy that Sterzel 2 records the association of Gomphostrobus 

 with Dadoxylon wood. Potonie, who at first overlooked Marion's 

 paper, proposed the name Psilotiphyllum to give expression to his 

 opinion that the Permian plant is a Palaeozoic member of the 

 Psilotales, a conclusion based on insufficient evidence. We have 

 no definite information with regard to the nature of the organ 

 borne on the sporophylls. The same author compares the sporo- 

 phylls of Gomphostrobus with the leaves of Sphenophyllum though 

 the verticillate disposition of the leaves of the latter genus is a well- 

 defined difference. It would seem, as Zeiller says, that Gompho- 

 strobus is probably allied to Walchia though its position cannot be 

 precisely determined without further data. 



A recent examination of some specimens from Lower Gondwana 

 rocks in India described by Feistmantel 3 as Voltzia revealed the 

 occurrence of some small distally forked leaves very similar to the 

 sporophylls of the European Gomphostrobus. 



1 Zeiller (92 2 ) A. p. 101, PI. xv. fig. 12; (06) B. p. 213, PL L. 



2 Sterzel (00) p. 6. 



3 Feistmantel (79 2 ) Pis. xxn. et seq. 



68. 



