32 GINKGOALES [CH. 



Greenland beds as Miocene,, but it has been suggested that they 

 may belong to the Eocene period 1 . 



Heer 2 also described specimens of Ginkgoites adiantoides from 

 beds, assigned to the Miocene period, in Sachalin Island. This- 

 species has been obtained from the Laramie series, a thick succession 

 of brackish water strata deposited on both sides of the Rocky 

 Mountains * extending from Mexico far into British North American 

 Territory' and including both Upper Cretaceous and Lower 

 Tertiary strata 3 . Leaves described by Lester Ward as Ginkgo- 

 laramiensis* and regarded by him as intermediate between G. adian- 

 toides and G. biloba are indistinguishable by any definite character 

 from G. adiantoides. Ward's species is also recorded by Knowlton 5 

 from the Montana formation, a series of beds formerly included in 

 the Laramie group, in Wyoming. Ginkgoites adiantoides occurs 

 in Upper Cretaceous beds in British Columbia and specimens 

 described as Salisburia pusilla Q by Dawson, which I believe to 

 belong to this species, were found in the Upper Cretaceous of 

 Vancouver Island. From beds of the same age Penhallow 7 has 

 described some wood as Ginkgo pusilla though it is not clear on 

 what grounds it is assigned to the genus Ginkgo. 



It is interesting to find leaves of this type recorded from Lower 

 Pliocene beds at Saint Marcel-d'Ardeche in France 8 and from 

 Upper Pliocene beds in the Lower Main valley in Germany 9 . 



It is therefore abundantly clear that trees, apparently indis- 

 tinguishable as regards the form of the leaves from Ginkgo biloba, 

 nourished as recently as the Pliocene period in western Europe 

 and in the Eocene period grew as far north as latitude 70. 



Records of seeds referred to Ginkgo are very meagre and add 

 nothing of importance to our knowledge of Tertiary species. Some 

 pyritised seeds were described by Ettingshausen and Gardner 10 



1 White, D. and Schuchert (98) p. 367. 



2 Heer (78) v. p. 21, PL n. figs. 710. 



3 Ward (87) p. 15, PL xxx. figs. 5, 6; (85) PL xxxi. pp. 46. 



4 Ibid. PL i. fig. 4 ; PL xxxi. fig. 4. 



5 Knowlton (00) p. 31, PL iv. figs. 710; PL v. fig. 5. 



6 Dawson (93) p. 56, PL vi. figs. 11 14. Heer's species Ginkgo pusilla is 

 founded on Jurassic leaves; Heer (77) ii. p. 61. 



7 Penhallow (02) p. 43, Pis. xn., xra. 8 Depape (13). 

 9 Engelhardt and Kinkelin (08) p. 196, PL xxm. fig. 18. 



10 Ettingshausen (79) p. 392. 



