XXXIX] CTENIS 581 



Ctenis fallax Nathorst. 



This Scanian Rhaetic type'-, including Anthrophyopsis crassi- 

 nervis, A. Nilssoni, and probably A. obovata Nath., is characterised 

 by very large obtusely pointed pinnae reaching at least 20 cm. 

 in length and over 3 cm. in breadth. The veins are often 2 mm. 

 apart and form long polygonal meshes. Nathorst figures small 

 circular patches on the surface of the lamina. Raciborski^, on 

 slender evidence, refers a fragment from the Jurassic of Cracow 

 to this species. 



Ctenis hungarica Staub. 



A species* characterised by very large fronds reaching 2 met., 

 bearing broad hnear pinnae almost at right-angles and attached 

 to the rachis by decurrent bases, attaining a length of 21 cm. 

 and a breadth at the base of the lamina of 3-5 cm. and 4 cm. a 

 short distance from the acute apex. The veins are parallel to 

 the edge of the lamina, but Staub does not appear to have seen 

 distinct anastomoses. It is not improbable that Staub's species 

 may be identical with C. asplenioides (Ett.) from the Lias of 

 Hungary, specimens of which are preserved in the ^ficole des 

 Mines, Paris. 



Ctenis asplenioides (Ettingshausen). 



This species was first described by Ettingshausen* from 

 Liassic strata in Austria as Taeniopteris asplenioides and compared 

 by him to large simple fronds of Asplenium nidus but distin- 

 guished by a deeply dissected lamina. Schenk^ found that the 

 veins anastomose and adopted the name Ctenis. In habit very 

 similar to C. sulcicaulis, but the pinnae are much broader, exceeding 

 4 cm., and the veins are 3 — 5 mm. apart. Only the basal part 

 of the segments is figured by Ettingshausen. Specimens in the 

 Ecole des Mines, Paris, from Hungary have pinnae nearly 40 cm. 

 long and 2-5 cm. in breadth, the parallel veins being connected 

 by a few oblique branches. Both Ettingshausen and Schenk 

 speak of small circular sori on the lower epidermis, though these 

 are not figured nor were any sporangia obtained. This species 



1 Nathorst (86) p. 89, Pis. vii., viii., xi., xix. 



2 Baciborski (92) PI. ii. fig. 2. ^ gtaub (96) 



' Ettingsha,usen (51) Pis. xi., xii. = Schenk (682). 



