xxi] 



CLADOPHLEBIS 



345 



sents an impression from the Inferior Oolite rocks of the 

 Yorkshire coast in which the exposed upper surface of the 

 pinnules shows a series of parallel ridges following the course 

 of the lateral veins and no doubt formed by oblong son on the 

 lower surface. There can be little doubt that the specimen 

 figured by Lindley and Hutton and by others as Pecopteris 

 undans^ is, as Nathorst suggests, a portion of a fertile frond of 

 C. denticulata. A fertile specimen of a frond resembling in 

 habit C. denticulata, which Fontaine has described from the 



Fio. 258. Fertile pinnae of Cladophlehis denticulata. (From a Yorkshire 

 specimen in the Sedgwick Museum, Cambridge.) 



Jurassic rocks of Oregon as Danaeopsis Storrsii^, exhibits, as 

 that author points out, a superficial resemblance to the specimen 

 named by Lindley and Hutton Pecopteris undans. There is, 

 however, no adequate reason for referring the American 

 fragment to the Marattiaceae. In the absence of sporangia we 

 cannot speak confidently as to the systematic position of this 

 common type; but there are fairly good grounds for the assertion 

 that some at least of the fronds described under this name 

 are those of Osmundaceae. The English spiecimen shown in 



1 Lindley and Hutton (34) A. PI. cxx. 



- Fontaine, in Ward (05) PI. xv. figs. 6—9. 



