Vol. 69. J OUR KNOWLEDGE OF WEALDEN FLORAS. 95 



Schizseaceae (?). 



Cladophlebis browniana (Dunk.). (PI. XIII.) 



(Fairlight, Dawson Coll.) 



1846. Pecopteris broivniaila Dunber, 'Monographie der Norddeutschen Weal- 

 denbilduiig ' p. 5 & pi. viii, tig. 7. 



■ . P. ungeri Danker, ibid. p. 6 & pi. ix, fig. 10. 



1869. P. dunkeri Schimper, ' Traite de Paleontologie Vegetale ' vol. i, p. 539. 



It has been pointed out by Lester Ward a that, as the specimens 

 figured by Duuker as Pecopteris ungeri are generally considered to 

 be indistinguishable from those assigned to Cladophlebis dunkeri, 

 the older name should be retained : Mr. Berry, in his recent 

 monograph, also conforms to the strict rule of priority. In the 

 description of the Wealden plants in the British Museum (Natural 

 History) attention was drawn to the difficulty of separating certain 

 specimens referred by authors to CI. browniana and CI. dunkeri, but 

 both names were retained. A further examination of the English 

 material led me to adopt the name CI. browniana " in a wider sense, 

 as including examples previously assigned to CI. dunkeri. Mr. Berry, 

 while agreeing with me as to the close similarity between CI. 

 browniana and CI. dunkeri, prefers to retain both specific names, 

 CI. ungeri being substituted for CI. dunkeri. 3 



The photographs reproduced in PI. XIII show portions of an 

 exceptionally large and instructive specimen in the Dawson 

 Collection. Pig. 1 shows a rachis, or pinna-axis, bearing alternate 

 linear-lanceolate pinna? with straight or slightly-falcate linear 

 pinnules, most of which have a crenulate margin, while others are 

 entire. This piece of frond is interesting, because of the evidence 

 it supplies of a transition between the two forms of segments, 

 supporting the view that the fern described by Dunker as Pecopteris 

 browniana is not specifically distinct from CI. dunkeri (Schimp.). 

 The larger piece shown in fig. 2 bears short pinnate branches in 

 which the crenulate pinnules of fig. 1 are replaced by short and 

 entire ultimate segments. The close association of the two speci- 

 mens (figs. 1 & 2), each of which is only reproduced in part, on 

 one piece of rock renders it almost certain that they belong to 

 one large frond. 



The following references afford further illustration of the 

 difficulty — or, indeed, impossibility — of separating Cladophlebis 

 browniana and CI. dunkeri : — 



Fontaine in Ward (05) pi. lxv, figs. 9-11 (CI. browniana), figs. 15 & 16 

 (CI. ungeri): Nathorst's and Yokohama's Japanese specimens, Nathorst (90) 

 pi. iv, figs. 2, 6, pi. v, fig. 5, & pi. vi, fig. 4 ; Yokoyama (94) pi. xiv, figs. 2 & 3 : 

 also Saporta (94) pi. xii, figs. 2 & 3 (Pecopteris browniana). The fern figured 

 by Dr. Yabe from Jurassic beds in Korea as CI. Jcoraiensis, may be an 

 example of CI. browniana [Yabe (05) pi. ii, fig. 1 & pi. iii, figs. 12-13]. 



1 Ward (05) p. 228, footnote 1. 



2 Seward (08) p. 11. 



3 Berry (IP) p. 257. 



