XLV] ELATIDES 273 



absence of cones the latter species is retained in Pagiophyllum. 

 From the Wealden species E. curvifolia, E. Williamsonis differs in 

 its stouter and more crowded leaves though the differences are 

 slight both in the cones and vegetative shoots. In all probability 

 this species is represented in several Jurassic floras, but unless 

 cones are present specimens should be referred to Pagiophyllum. 



Elatides curvifolia (Dunker). 



Dunker^ first described this Wealden type (fig. 743) from North 

 Germany as Lycopodites and it was referred by Ettingshausen^ to 

 Araucarites, the generic name, though probably correctly express- 



FiG. 743. Elatides curvifolia. (After Nathorst; nat. size.) 



ing the position of the fossil Conifer, being used without adequate 

 reasons. The identity of the cones discovered by Nathorst* in 

 the Wealden or Upper Jurassic beds of Spitzbergen with those on 

 which Heer founded the genus Elatides led to the adoption of that 

 generic term. Nathorst's discovery of several fertile branches 

 justifies his reference of Heer's specimens from Spitzbergen 

 described as Sequoia Reichenhachii^ to Elatides curvifolia, as also 

 the employment of Dunker's specific term for Elatides ovalis and 

 E. Brandtiana Heer. The cones of E. curvifolia are cylindrical or 

 oval and it is suggested by Nathorst that these forms might be 

 regarded as varieties, the oval form being spoken of as var. ovalis 



1 Dunker (46) A. p. 20, PI. vn. fig. 9. 



2 Ettingshausen (52) PL n. 



» Nathorst (97) pp. 35, 58, Pis. i., n., iv., vi. 



' Heer (75) ii. PI. xxxvi. figs. 1 — 8; PI. xxxvii. figs. 1, 2. 



s. IV 18 



