SPHENOPTEEIS. Ill 



The figure gives the impression of a filmy fern, and in the 

 light brown stain on the rock surface, representing the leaf 

 lamina, we have just that kind of imprint which might be looked 

 for in a Hymenophyllaceous type of fern. Attention has already 

 been called to the danger of trusting too much to such resem- 

 blances, which are frequently nothing more than expressions of 



FIG. 10 (V. 2327). Enlarged 4 times. 



the different effects of the diversity in texture and porosity of the 

 rock matrix. The single pinnule shown in the woodcut agrees 

 very closely with one figured by Potonie 1 in a Carboniferous fern, 

 Sphenopteris HoBninghausi, Brong. , var. Larischiformis, Pot. ; but 

 it is not for a moment suggested that the two species have any 

 natural affinity whatever. Ecclesbourne. Rufford Coll. 



V. 2162. Woodcut, Fig. 11. 



Probably a pinna from the basal portion of a frond. Pinnules 

 ovato-lanceolate and lobed. The venation is fairly distinct, but, as 

 is usually the case with carbonaceous impressions on clay, not nearly 



FIG. 11 (V. 2162). Enlarged 3 



so well marked as on the ironstone. The figure shows a median, 

 and less marked lateral veins. Some of the pinnules in Fitton's 

 type specimen correspond fairly closely with those represented in 



1 Jahrb. k. preuss. Geol. Landesanst, 1890, p. 23, pi. vii. 



