178 ' ME 



AND MISS N. BANCEOFT ON 



fossil remains with wliicli he had to deal were, however, very fragmentary; little or 

 nothing could be made out as to the macroscopic characters of the fronds whose cuticular 

 structure is figured, and from his figures one is led to suppose that the preservation of 

 the fragments or the methods of treatment were not of the best. In the cases figured 

 the walls of the epidermal cells are all represented as straight, and the stomata figured 

 do not allow any close comparison with the examples now before us. It would appear 

 that the forms figured on his Taf. 7. figs. 1-6 are allied to Thinnfeldia , but in no other 

 cases are the stomata sufficiently well represented. 



Schenk, in his Fossil Mora of Frankonia (1867), made a great advance in the study 

 of cuticles ; he described and gave accurate figures of the cuticles of a number of forms, 

 including Twniopteris stenoneura, Thinnfeldia spp., Nilssonia polymorpha, OtozamUes 

 (Ofopteris) BucUandi, Pterophyllum spp., several conifers and ferns. He does not give 

 many good figures of preparations showing stomatal structure, but he was the first to 

 observe the sinuous walls of the cells in various species of Tterophyllum and in 

 Otozamites. He mentions that he has made preparations from the English species 

 O. acuminatus, O. Beani, and O. graphicus, also of the English species of TcBuiopteris, 

 which was found to be comparable with the Otozamitean structures *. He gave some 

 short descriptions of stomata, noticing that they occur usually on one side of the lamina 

 only; but there are many points of importance on which we can obtain no information 

 from his work. The same author subsequently figured the cuticles of Dioonites 



Bunherianus (Goep.) f. 



Zeiller (1882) described and figured the epidermal structure of a Thinnfeldia 

 {Cycadopteris Brauniana) and Frenelopsis Soheneggeri ; he has also figured a small 



piece of a cuticle of a Palaeozoic Pterophyllum (Zeiller, 1906). 



In his ' Jurassic Elora of the Yorkshire Coast ' Prof. Seward (1900, p. 234, fig. 43) 

 has given a good figure of part of a lower cuticle of Ctenis sp. The form of the 

 epidermal cells, often bearing papillae, was well shown ; the stomata were not clearly 

 seen, but there were depressions representing the cavities in which the stomata were 

 sunken. 



Most of the recent observations on the epidermal structures of Mesozoic Cycadean 

 fronds have been made by Prof. Nathorst. He has described and figured the cuticles of 

 species of the following genera: — Bictyozamites, Bseudocycas^ Btilozamites {Ctenozamites), 

 and NilssoniaX. He has given many excellent photographs of these, but has not yet paid 

 special attention to the structure of the stomata, which is one of the most important 

 features from the point of view of the present inquiry. As will be seen later, many of 

 the cuticles now described and figured can be very closely compared with the specimens 

 from the Scandinavian plant-beds. This is especially the case in the instance of Bictyo- 

 zamites Johnstrupi from Bornholm and Bictyozamites Sawelli from Marske. The close 

 similarity between these forms, and also the similarity between specimens of other types 

 occurring in both the Lower and Middle Estuarine beds of difl'erent parts of North 



* Schenk (1867), p. 165. 



t Schenk (1871), pi. xv. figs. 2-4. 



+ 



m 



