14 CYCADACEJE. 



Cycadacea were represented by many large and striking species. 

 Further reference will be made to the Lower Cretaceous cycads in 

 the general review of the Wealden flora at the end of this volume. 

 Throughout the Cretaceous and Tertiary series we have evidence 

 of a decline in the relative importance and numerical proportion 

 of the Cycadacece. It has been suggested that possibly the paucity 

 of species may in some measure be explained by our very imperfect 

 acquaintance with tropical and subtropical Cretaceous and Tertiary 

 plant-bearing strata ; l it may be that the rocks of these eras were 

 deposited under climatal conditions which were not favourable to 

 a rich development of cycads. Heer 2 has described various frond 

 fragments from Tertiary beds which are not particularly satis- 

 factory as records of cycadean species. The two species Nilssonia 

 Serotina, Heer, and N. pygmaa, Heer, from the Miocene flora of 

 Sachalin Island, are both founded on fragments which may possibly 

 belong to that doubtful genus in which they have been placed. 

 From the Upper Fresh-water Molasse of Schaffhausen, the same 

 author describes a structureless stem as Cycadites JSseheri, Heer ; 3 

 the appearance of the scale-covered surface lends some support to 

 this determination, but the specimen is too imperfect to be of any 

 particular importance. Heer figures a fragment of a frond from 

 Lausanne under the name Zamites (Dioon ?) tertiariw, 3 founded 

 on a poor and fragmentary specimen. Three species of Tertiary 

 cycads are figured by Saporta and Marion in their V Evolution 

 du regne vegetal : * one of these is assigned to Zamiostrolus Z, 

 Saportanus, Schimp., and may possibly be rightly described as 

 a cycadean cone, but its precise nature cannot be definitely 

 ascertained. The other two species, Zamites epibius, Sap., and 

 Encephalartos Gorceixianus, Sap., are most probably true cycads. 

 Ettingshausen's New Zealand specimen, described as Zamites sp. ? 

 cannot be accepted as trustworthy evidence of a Tertiary cycad. 5 

 From Australia the same author records Anomozamites Muelleri* 

 Ett., a species based on small fragments of what may be a 



1 Solms-Laubach, p. 85. 



2 Flor. foss. Arct. vol. v. (Flor. Sachalin), pp. 19 and 21, pi. ii. figs. 1-6. 



5 (A.) Fl. Tcrt. Helvet. p. 46, pi. xv. and pi. xvi. fig. 1. 

 4 Les Phanerogames, vol. i. p. 116. 



6 Ettingshausen (1), p. 13, pi. i. fig. 10. 

 6 (2), p. 9, pi. viii. figs. 19-22. 



