24 SkwarT), /urass/c Pla^its in the MancJiester Museum. 



I have been led to include Cyclopteris Huitoni Stcrnb. 

 and some other 'species' under Ginkgo digitata as the 

 result of an examination of the leaves of the solitary 

 recent species Ginkgo biloba L., which show considerable 

 variation in the form and dissection of the lamina; a 

 careful comparison of numerous Jurassic specimens has 

 convinced me that it is impossible to found satisfactory 

 specific distinctions on the depth or number of the seg- 

 ments into which the lamina is divided.' 



The specimen represented in pi. ii., fig. 5, affords an 

 interesting example of this species of Ginkgo, which had a 

 wide geographical range in the Jurassic period. This leaf 

 is larger than the majority of the English specimens, and 

 agrees fairly closel}- with a specimen described by 

 Eichwald, from Russia, as Cyclopteris incisa; it measures 

 8 cm. across, and the lamina is divided into several short 

 and comparatively broad lobes. 



^ An account of tlu- structure and geological liistory of Ginkgo biloba L. 

 is puMisIicd in llie Annals of Bo/any, March, 1900. 



