280 CONIFERALES INCERTAE SEDIS [CH. 



which FUche regards as leaf-bases and compares with those on 

 Araucarian stems. While admitting the possibility that the wood 

 belongs to Gomphostrobus or some Cordaitean species Fliche con- 

 siders Walchia the most likely genus. The comparative closeness 

 of the leaf-bases would seem to be a difficulty : in stems as large 

 as the type-specimen of W. valdajolensis one would expect to find 

 the leaf-bases more widely separated and tangentially stretched. 

 It is by no means unlikely that the supposed surface-features may 

 belong to a deeper zone of the cortex of a partially decorticated 

 stem ; but in any case they do not suggest a stem of Cordaites or 

 Mesoxylon. It is impossible to assign the species with confidence 

 to Walchia though Fliche may be correct in his opinion as to the 

 likelihood of that being its true position. The generic name 

 Araucarites implies a degree of affinity which has not been estab- 

 lished and the designation Dadoxylon would be more in keeping 

 with the facts. 



Walchia is especially characteristic of Permian floras though 

 it has been shown to occur in the Stephanian of several countries. 

 In Britain Walchia is recorded from a very few Permian "^ and 

 Upper Coal Measures^ localities. We cannot speak with confidence 

 as to the position of the genus : the striking resemblance in the 

 system of branching and in the foliage-shoots to certain species of 

 Araucaria at once suggests a possible affinity to the Araucarineae, 

 and this slender basis of comparison receives support from the 

 occurrence in a few instances of single seeds on the upper face of 

 sporophylls and from the Araucarian type of pitting in wood 

 associated with Walchia branches. It may fairly be said that 

 although proof is lacking there is a strong presumption in favour 

 of regarding this Permo-Carboniferous genus as more nearly allied 

 to the Araucarineae than to any other family of Gymnosperms. 



Walchia ■piniformis (Schlotheim). 



This, the commonest species, was originally described by 

 Schlotheim as Lycopodiolithes piniformis^: it occurs in both 

 Permian and Stephanian strata*. The pinnately branched shoots 



1 Vernon (12) p. 607. 2 Kidston (02) B. 



3 Schlotheim (20) A. p. 415, PI. xxiii. fig. 1 a; PI. xxv. fig. 1. 

 ^ £.?.Stefani(01)p. Ill; Weisa, C. E. (72)p. 179; Heer (76) A. p. 57 ; Goeppert 

 (65) p. 236; Grand'Eury (77) A. p. 514. 



