102 CLADOPHLEBIS. 



the upper end are very similar to Schenk's later figures of 

 Pecopteris Browniana, pi. xxvi, figs. 3-5, l and, in view of the 

 more perfect nature of the English material, and the additional 

 information it affords as to the character of the fern, I have 

 regarded these specimens as portions of larger pinnae of C. 

 Dunkeri. The figure given by Geyler of Pecopteris exiliforme, 

 from Japan, distinctly resembles C. Dunkeri, and does not suggest 

 a plant with a well-marked specific difference. 



Fontaine's examples of Aspidium. Dunkeri undoubtedly belong to 

 that species, but the fertile pinnule, pi. xxii. fig. 90, 2 on which 

 apparently the reference to Aspidium is based seems hardly suffi- 

 cient evidence for assuming identity with the recent genus. I 

 have included under C. Dunkeri some of the figures of Pecopteris 

 Browniana given by Fontaine ; probably more than those quoted in 

 the above list of synonyms might be referred to Schimper's species. 

 This inclusion of some of Fontaine's examples of P. Browniana, as 

 well as some of those referred by Schenk to the same species, is the 

 result of the more perfect material recently acquired which proves 

 the organic connection of different parts of fronds previously re- 

 garded as distinct. Yokoyama, in describing his Japanese plant, 

 adopts Phillips' Jurassic species, P. exilis, z for certain fern frag- 

 ments which I am inclined to consider identical with C. Dunkeri ; 

 the figure of P. obtusifolia, L. and H., 4 which is included by 

 Phillips under P. exilis, and the pinnae of the latter species 

 probably represent some other fern than that figured by Yokoyama. 

 His specimens cannot well be separated from the present species. 

 Nathorst compares his species, P. Geyleriana, from Japan, with 

 P. exiliforme, Gey. (=P. exilis of Yokoyama); this, too, appears to 

 me inseparable from C. Dunkeri. Cf. Nathorst, pi. iv. figs. 2-6, 5 

 and PL VII. Fig. 3 of the present Catalogue. The fragment 

 mentioned by Nathorst as Pecopteris, sp., 6 is compared by him to 

 P. exilis and P. Dunkeri. 



1 Palaeontographica, vol. xxiii. 



2 Potomac Flora. 



3 Geol. Yorks. p. 210, pi. viii. fig. 16. This species has recently been referred 

 to a new genus, Klukia, Raciborski, Bot. Jahrb. vol. xiii. 1891, p. 5. 



4 Fossil Flora, vol. iii. pi. clviii. 



8 Denkschr. k. Ak. Wiss. math.-nat. 01. vol. Mi. 1890. 

 6 Ibid. pi. vi. fig. 4. 



