124 FOSSIL PLANTS. 



Alethopteris lanceolata. 



Lesquereux, Eeport Geol. Survey of Illinois, vol. iv. p. 398, pi. xin. figs. 



1-3. 

 Goniopteris elliptica. 



Fontaine and White, Perm, or Upper Garb. Flora, p. 83, pi. xxx. fig. 1. 



Goniopteris oblong a, (?). 

 Fontaine and White, Perm, or Upper Garb. Flora, p. 83, pi. xxx. figs. 3-5. 



Remarks. The pinnae in this species differ much in appearance, being 

 entire or pinnate, according to their position on the frond. 



Pecopteris longifolia, Brongt., is referrable to his Pecopteris unita. In the 

 true Alethopteris (P.) longifolia, Sternb.,* the veins are only once forked, 

 whereas in P. unita, Brongt., the main vein, throughout its whole course, 

 gives off several simple lateral veinlets, which extend to the margin of the 

 pinna when the pinnules are confluent, or to the apex of the pinnule where 

 they are separate. 



Stur,t in referring to P. (Diplazites) unita, says it is an imperfectly and 

 little-known species, whose relation to P. (Diplazites) longifolius, Brongt., 

 and P. (Diplazites) emarginata, Gbpp. sp., is still undecided. 



Weiss places the figure of Pecopteris emarginata, given by Bunbury, J under 

 P. (Stichopteris) longifolia, but Bunbury's figure, pi. vi. fig. 4, is identical in 

 all essential respects with the figure of Pecopteris (Cyathocarpus) unita given 

 by Weiss on his pi. xii. fig. 5, so if these two ferns are really specifically 

 distinct, he appears to be in error in writing P. emarginata, Bunbury, with 

 his P. (Stichopteris) longifolia. 



Lesquereux, after comparing the characters of P. elegans, Germar, and 

 P. unita, Brongt., says : " After the examination of many hundred speci- 

 mens, it is impossible to point out a single trait which could be described as 

 distinctive of one of these spepies. I therefore consider this P. elegans, Germar, 

 as a variety of P. unita, Brongt." ' 



Pecopteris lanceolata, Lesqx. appears to be merely the upper portion of a 

 frond of P. unita, Brongt., and similar to what has been figured by Weiss as 

 P. (Stichopteris) longifolia.\\ 



Many Authors regard P. unita, Brongt., P. longifolia, Brongt. (non Sternb.), 

 P. emarginata, Gopp. sp., and P. elegans, Germar, as distinct species, but 

 though I have examined a number of specimens, both Foreign and British, I 

 am unable to find any definite character by which they can be distinguished, 

 and therefore include them all under P. unita, Brongt. 



Horizon. Coal Measures. 



Localities. Foreign. France : Sa6ne-et-Loire, Blanzy ; Allier. Saxony : 

 Wettip. United States : Mount Carbon, Penn- 

 sylvania ; Illinois, Mazon Creek, Grundy Co. 



Pecopteris Defrancii, Brongniart. 

 Pecopteris Defrancii. 



Brongniart, Prodrome, p. 58. 



Hist. d. Vege"t. Foss. p. 325, pi. cxi. pi. cxii. fig. 1. 



Heer, Flora Foss. Helv. p. 35. 

 Eost, De Fil. Ectypis, p. 25. 

 Alethopteris Defrancii. 



Bronn, Index Palseont. p. 23. 

 Goppert, Syst. Fil. Foss. p. 317. 



* Vers. pi. xxxvi. fig. 1. 



t Morph. u. Syst. d. Culm u. Carbonfarne, p. 143. 



I Quart. Journ. Geol. Soc. vol. ii. pi. vi. 



Report Geol. Survey of Illinois, vol. iv. p. 403. 



|| Loc. cit. pis. ix. x. figs. 7, 8. 



