CLADOPHLEBIS. 141 



Bean's name Pecopteris scarlurgensis was applied by him to 

 specimens clearly identical with C. denticulata. 



In Fontaine's Potomac Flora there are several specimens named 

 CladopMehis falcata ; ' these have the same form of frond as 

 C. denticulata, but there is hardly enough evidence, without 

 having access to the specimens, to warrant the inclusion of 

 the Potomac species among the sj-nonyms of Brongniart's plant. 

 Fontaine also figures some fronds which he names C. denticulata, 

 but speaks of this species as new, while drawing attention to 

 published figures of Pecopteris denticulata by Heer.^ 



A specimen in the British Museum Collection (V, 640) from 

 Steierdorf im Banat, named Pecopteris whithiensis, bears a very 

 close resemblance to CladopMelis denticulata, but the pinnules 

 appear to have an entire margin. There are various other fossil 

 fronds which may be compared with CladopMelis denticulata, e.g. 

 Asplenium distans as figured by Yokoyama ' from Japan ; but 

 without more trustworthy evidence than a similarity in the form 

 of the sterile pinnse there must always be an element of uncertainty 

 in our comparisons.* 



The point of most interest as regards the comparison of 

 CladopMehis denticulata with recent ferns is the evidence afforded 

 by the nature of the fertile pinnules of the fossil species. We 

 know nothing as to the structure of the sporangia, and our 

 comparisons must rest solely on the form of the fertile segments 

 and the disposition of the sori. It is among the Polypodiaoese that 

 we find the nearest resemblance to the fossil species ; in some species 

 of Asplenium, e.g. A. luguhre,^ also Phegopteris decussata (L.),* the 

 fertile pinnules with their thin linear sori parallel to the lateral 

 veins agTce closely with those of CladopMehis denticulata (vide 

 PI. XX. Pig. 35). Eaciborski has suggested the probability of 

 CladopMehis denticulata ' and some other species of the genus being 



1 Fontaine (89), pi. v. figs. 1-6. 



» Loc. cit. p. 71. 



' Yokoyama (89), pi. xiv. fig. 1. 



* Some specimens recently sent to me for identification from South Africa, by 

 Mr. Rogers, of the Geological Commission, Cape Toivn, appear to be identical 

 with CladophUUs denticulata. 



5 Hooker (61), pi. iii. 



» Christ (97), p. 273. 



' Eaciborski (91), p. 2. 



