XL] GINKGOITES 27 



bilobed and each half may be similarly divided: the segments 

 are obtuse and not truncate (fig. 642, A) ; the veins are approxi- 

 mately 1 mm. apart. The walls of the epidermal cells are straight 

 and not sinuous ; the stomata (fig. 642, B) are practically confined 

 to the lower surface and are less numerous than in Ginkgo hiloba. 

 The guard-cells are surrounded by a group of broadly triangular 

 cells with papillose, thickly cuticularised, inner walls, but the 

 overarching papillae are rather less prominent than in G. digitata. 

 It is interesting to find short secretory tracts at intervals in the 

 mtercostal regions of this species agreeing with those in the leaves 

 of the recent species. A leaf described from Jurassic rocks in 

 Amurland cs Ginkgo sp., cf. G. Obrutschewi^ agrees closely with 

 the type-specimens. 



Ginkgoites crassipes (Feistmantel). 



This Upper Gondwana species (fig. 643, B) was described from 

 the Madras coast as Ginkgo crassipes'^. An examination of the 

 type-specimens enables me to confirm generally the accuracy of 

 Feistmantel's figures except in one point, namely the supposed 

 presence of a median ridge extending from the petiole through the 

 lower third of the lamina, which gives the impression of a midrib : 

 this is merely a shallow groove that is clearly accidental. The 

 leaves appear to be entire; the lamina is obcuneate and passes 

 into a fairly stout petiole ; the veins are occasionally forked and 

 approximately 0-5 mm. apart. The piece of lamina described by 

 Feistmantel as Ginkgo sp.^ may be specifically identical with this 

 species. 



Ginkgoites pluripartita (Schimper). 



This Wealden species was first described by Hunker* as 

 Cyclopteris digitata Brongn. and Ettingshausen^ also regarded the 

 German specimens as identical with the EngUsh Jurassic type. 

 Schimper^ proposed the name Baiera pluripartita because of the 

 deeply divided lamina and the comparatively narrow segments : 



1 Seward (12») PI. i. fig. 9. 



2 Feistmantel (77) p. 197, figs. 6, 7; (79) p. 31, Pis. xv., xvi. 



3 Feistmantel (79) PI. xvi. fig. 12. 



■■ Dunker (46) A. p. 9, PI. i. figs. 8, 10; PI. v. figs. 5, 6; PI. vi. fig. 11. 

 5 Ettingshausen (52) p. 12, PI. iv. fig. 2. 

 « Schimper (69) A. p. 423. 



