100 GENERA OF UNCERTAIN POSITION [CH. 



of Pennsylvania, but neither is represented by very satisfactory 

 specimens: Dicranophyllum dichotomum Lesq. is founded on a 

 dichotomously branched shoot bearing long and narrow leaves in 

 the apical region only and very similar in appearance to Lepido- 

 dendron except in the branched lamina. The second species 

 D. dimorphum Lesq. is represented by leaves and branches, which 

 however are not well preserved. The peculiar subdivision of the 

 apical portion of the laminae suggests a simple leaf irtjjth a frayed 

 termination. 



Dicranophyllum glabrum (Dawson). 



Under this name Dr Stopes^ has recently described a well- 

 preserved leaf from the Westphalian series of New Brunswick. 

 The specific name was first applied by Dawson^ to specimens which 

 he referred doubtfully to Psilophyton. The type-specimen is 9 cm. 

 long and 3 mm. broad at the base and the lamina is repeatedly 

 branched. This specimen bears a close resemblance to the leaf 

 from Autun described by Renault as Trichopitys Milleryensis^. 



The imperfect specimens described by Dawson* from Devonian 

 rocks in Queensland as Dicranophyllum australicum and sub- 

 sequently figured by Jack and Etheridge^ consist of a slender 

 axis, 3 mm. wide, with elongate leaf-bases bearing leaves 3 mm. 

 long with two widely divergent apical segments like those charac- 

 teristic of the sporophylls of Gomphostrobus. The fragments have 

 no claim to be included in Dicranophyllum. 



There has been confusion between Dicranophyllum and Gom- 

 phostrobus^ : as shown by drawings reproduced by Potonie' of 

 specimens of Gomphostrobus from the Permian of Thuringia, there 

 is a close resemblance in habit between the two genera, but in 

 Gomphostrobus the foliage-leaves are falcate and entire, while the 

 bifurcate sporophylls differ from the leaves of Dicranophyllum in 

 their widely divergent and small apical fork. 



1 Stopes (14) p. 79, PI. xvin. fig. 47. 



2 Dawson (62) p. 315: for other references, 'see Stopes loc. cit. 



3 Renault (96) A. p. 378 ; (93) A. PI. Lxxxn. fig. 2. 

 ' Dawson (81) A. p. 306, PI. xm. figs. 15, 16. 



5 Jack and Etheridge (92) B. p. 49. 



« Schenk (90) A. erroneously includes Sigillariostrohus bifidus Geinitz, (73) 

 PI. in. figs. 5 — 7, in Dicranophyllum. See also Sterzel (93) A. p. 111. 

 ' Potonie (93) A. PI. xxvin. figs. 1, 2. 



