RADSTOCK SERIES OF THE SOMERSET AND BRISTOL COAL FIELD. 385 



Alethopteris Serlii, Brongniart, sp. 



Alethopteris Serlii, Sternb., Vers., ii. p. 144. 



Alethopteris Serlii, Lesqx., Coal Flora of Pennsyl., vol. i. p. 176, pi. xxix. figs. 1-5. 



Alethopteris Serlii, Zeiller, Veget. foss. d. terr. liouil., p. 75, pi. clxiii. figs. 1, 2. 



Pecopteris Serlii, Brongt., Hist. d. veget. foss., p. 292, pi. Ixxxv. 



Pecopteris Serlii, L. & H., Fossil Flora, vol. iii. pi. ccii. 



Remarks. — This fern is extremely abundant — of so frequent occurrence that 

 one can scarcely split a slab without finding some fragments of it. 

 Bkongniart notices two varieties — 



(a) Europoea — with obtuse pinnules. 



(b) Americana — with acute pinnules. 



The first variety he received from near Bath and Dunkerton, and the latter 

 from Wilkesbarre, Pennsylvania. 



Both of these forms are equally common in the Radstock Series, but do not 

 form real varieties, for on a specimen from Radstock some of the pinnse are 

 var. Europoea and others var. Americana ; and further, even on the same pinna 

 I have observed that the pinnules on one side of the rachis were acute, and on 

 the other shorter and obtuse. 



Localities : — Radstock ; Braysdown Colliery ; Huish Pit ; Wellsway Pit ; 

 Upper Conygre Pit ; Lower Conygre Pit ; Camerton ; Dunkerton. 



Alethopteris Grandini, Brongniart, sp. 



Alethopteris Grandini, Grand' Eury, Flore Carbon, du Depart, d. la Loire, p. 107. 



Alethopteris Grandini, Zeiller, Flore foss. du Bassin liouil. de Valenciennes, pi. xxxviii. figs. 1, 2. 



Pecopteris Grandini, Brongt., Hist. d. veget. foss., p. 286, pi. xci. figs. 1-4. 



Remarks. — This species is very rare, only four or five specimens having 

 come under my notice. 



Localities: — Radstock; Braysdown Colliery; Wellsway Pit; Upper Conygre 

 Pit. 



Alethopteris aquilina, Schlotheim, sp. 



Alethopteris aquilina, Schimper, Traited. paleont. veget., vol. i. p. 556, pi. xxx. figs. 8-10. 



Pecopteris aquilina, Brongt., °Hist. d. veget. foss., p. 284, pi. xc. 



Filiates aquilina, Schlotheim, Flora d. Vorwelt, p. 38, pi. iv. fig. 7 ; pi. v. fig. 8. 



Remarks. — This species is rare in the Radstock Series, but the specimens 

 appear to me to be identical with Schlotheim's plant. It is true that this 

 author does not give details of the nervation, but dealing with his figures and 

 descriptions, the evidence seems to be in favour of Brongniart being correct 

 in identifying the plant he figures on pi. xc. as Schlotheim's species. 



Dr Stur holds a different opinion, and separates the plant figured by 

 Brongniart from Aletli. aquilina as founded by Schlotheim, and for Brong- 



