258 GINKGO. 



shown in Pig. 1, PI. IX., and still more closely with an unusually 

 large leaf of G. Aigitata in the Manchester Museum.^ Heer's 

 species 6. integrimcula, from Spitzbergen, is characterized by an 

 entire lamina, but, as Nathorst points out and Hear has himself 

 admitted, there ai-e no good grounds for regarding this form as 

 specifically distinct from G. digitata. In the York Museum there 

 is a very good specimen of a Ginhgo leaf from East Yorkshire., 

 agreeing in general shape with Pig. 1, PI. IX., but difiering in 

 having a lamina which is practically entire.'' 



The "Wealden leaves described by Dunker as Cyclopteris digitata, 

 and afterwards by Sohenk as Baiera multipa/rtita, may possibly 

 be specifically identical with the Lower Oolite G. digitata, but 

 it is safer to suggest their identity rather than to regard it as 

 well established. The wide range of Ginkgo digitata is shown 

 by the references in the above list of synonyms ; examples of 

 this species have been recorded from Siberia, Spitzbergen, Franz 

 Josef Land, Bomholm, England, Persia, Japan, and elsewhere. 

 The Arctic distribution of Ginhgo in Upper Jurassic times has 

 recently been extended by the discovery of several leaves named 

 by IN'athorst Ginhgo polaris '" ; some of them are very similar to 

 G. digitata, and differ only in their smaller dimensions, which 

 suggest an Arctic form of the English species. 



Before dealing with the flowers which may possibly belong 

 to Ginhgo digitata, we may briefly describe the fossil leaves 

 represented in the Museum Collection. 



39,211. PI. IX. Pig. 1. 



This unusually perfect specimen has a lamina 3'8 cm. deep and 

 6 cm. broad, with numerous and well-preserved forked veins. The 

 upper part only of the petiole has been preserved. Cf . Brongniart's 

 pi. vi. his, fig. 2 ; also Eichwald, pi. iv. fig. 6. The veins are very 

 clearly shown, and follow a course similar to that in the leaves of 

 the recent species. 



Oolitic Shale, Scarborough. Bean Coll. 



^ For a figure of the Manchester specimen, vide Seward (00), pi. ii. fig. S. 

 ' For a figure of this species, vide Seward & Gowan (00), pi. x. fig. 84. 

 ' Jfewton & Teall (97), pi. xxxviii. ; Nathorst (00). 



