382 ME ROBERT KIPSTON ON THE FOSSIL FLORA OF THE 



Dactylotheca plumosa, var. dentata, Brongt., sp. 



Pecoptens dentata, Brongt., Hist. d. veget. foss., p. 346, pis. cxxiii. cxxiv. 



Pecopteris dentata, Zeiller, Veget. foss. du terr. houil., p. 86, pi. clxviii. figs. 3, 4. 



Cyatheites dentatus, Geinitz, Vers. d. Steinlf. inSachsen, p. 26, pi. xxv. fig. 11 (in part); pi. xxix. 



figs. 10-12; pi. xxx. figs. 1-3 (4?). 

 Dactylotheca dentata, Zeiller, Ann. d. sc. not. Bot., 6 B ser., vol. xvi. p. 184, pi. ix. figs. 12-15; 



Bull. soc. geol. d. France, 3o ser., vol. xii. p. 201. 

 Senftenbergia plumosa, Stur, Carbon-Flora, pi. li. fig. 2 (3 1). 



Hem arks. — Two distinct forms of this fern occur in Britain, which have 

 usually been regarded as distinct species. In the above synonymy I have 

 attempted to separate them. 



This species was first described by Artis in 1825, under the name of 

 Filicites plumosus, and what I regard as a variety of Artis's plant was described 

 by Brongniart as Pec. dentata in 1828. 



After examining numerous specimens of Dactylotheca (Pec.) plumosa and 

 Dactylotheca (Pec.) dentata, I have been led to believe that Pec. dentata can 

 only be regarded as a well-marked variety of Pec. plumosa, a view that has 

 been indicated by Geinitz. # 



The two forms are, however, so well marked that a varietal name is 

 demanded in the case of one of them; hence Pec. dentata, Brongt., being of later 

 date than Dacty. plumosa, Artis, sp., Brongniart's form must be distinguished 

 as the variety, and is therefore here designated Dacty. plumosa, var. dentata. 



Dactylotheca plumosa, var. dentata, Brongt., sp., is extremely common in the 

 Radstock Series, and some very fine examples have been collected. The 

 typical form, Dactylotheca plumosa, Artis, sp., is very rare, having only been met 

 with at Timsbury. 



Dactylotheca plumosa, Artis, sp., is more plentiful in the Middle than in the 

 Upper Coal Measures, where the variety dentata is rare. 



Dr Stur seems to have confused Dacty. (Senftenbergia) plumosa with several 

 other species.t He unites Aspidites Silesiacus, Gopp.,J with Sphen. crena/</. 

 L. & H. Now Aspidites Silesiacus, Gopp. (specimens of which have been 

 kindly sent me by Prof. Weiss), is identical with Dactylotheca pdumosa, Artis, sp., 

 with which I have been able to compare it. On the other hand, Sphenopteri* 

 crenata, L. & H.,§ I believe to be an entirely different species. Again Stur, on 

 his plate li., gives three figures of Dactylotheca (Senftenbergia) plumosa; one of 

 these appears to be Dacty. phtmosa (fig. 1), the other two probably are referable 

 to the var. dentata. Stur further unites with his Dactylotheca (Senftenbergia) 



* Vers. d. Steinkf. in Sachsen, p. 26. 



f Carbon-Flora. 



\ Syst. fil. foss., p. 346, pis. xxvii. and xxxix. fig. 1. 



§ Lindley and Hutton, vol. i. pi. xxxix. ; vol. ii. pis. c. ci. 



