b] 



- 



XLI] CZEKANOWSKIA 65 



point, but the actual axis is not preserved ; the lamina is longi- 

 tudinally striated but no veins are shown either on the carbonised 

 lamina or in the magnified cuticle figured in the original description. 

 In the specimen reproduced in fig. 660, B the leaves are seen to 

 be attached to a short and relatively broad axis covered with 

 scale-leaves, one of which is shown bent over on one side of the 

 dwarf-shoot. The comparatively large size and the pendulous 

 position of the scales are characteristic features of the genus which 

 are well seen in figures of Czekanowskia published by Nathorst 1 . 

 This species was included by Saporta in Jeanpaulia and later 

 transferred to Trichopitys t while Zigno 2 and some other authors 

 regarded Solenites Murrayana as a species of Isoetes. The com- 

 parison with Isoetes suggested by the form of the leaves is not 

 borne out by the structure of the epidermal cells. Phillips 3 

 figured a specimen in 1829 as Flabellaria ? viminea : this specific 

 name though employed before the publication of Murrayana has 

 not been adopted by authors. Some of the specimens included 

 by Heer in his account of the species 0. rigida should be referred 

 to C. Murrayana, but in a previous description 4 of the species 

 I went too far in uniting C. Murrayana and C. rigida. In Czeka- 

 nowskia Murrayana the leaves, usually about 1 mm. broad but 

 sometimes narrower, reach a length of more than 17 cm. ; they 

 are unbranched and in this respect and in their slightly greater 

 breadth differ from C. rigida. 



The species is characteristic of Middle Jurassic floras. 



zekanowskia microphylla (Phillips). 



The specimen figured by Phillips 5 from the Yorkshire coast 

 as Baiera microphylla is undoubtedly identical specifically with 

 that reproduced in fig. 661, and both were formerly included in 

 Baiera Lindleyana 6 . The chief reasons for transferring them to. 

 Czekanowskia are the more acute angle of divergence of the filiform 

 segments, the difference in the shape of the leaves, the absence 

 of a petiole, and the occurrence of the leaves in a fascicle, a habit 

 not shown by any typical examples of B. Lindleyana though not 





1 Nathorst (06) PL n. 



- Zigno (56) A. p. 216. For other references, see Seward (00) B. p. 280. 



3 Phillips (29) A. PI. x. fig. 12. 4 Seward (00) B. p. 279. 



5 Phillips (75) A. p. 200, fig. 9. 6 Seward (00) B. p. 266. 



S. IV =: 





