106 SPHENOPTERIS. 



Potonie, 1 in a recent part of his serial papers on Carboniferous 

 ferns, has promised a revision of the genus Sphenopteris. 



1. Sphenopteris Fontaine!, sp. nov. 



Type. Piece of a ? frond. British Museum. PL VII. Fig. 2. 



Frond delicate, tripinnate, pyramidal in form ; pinnae alternate, 

 approximate, on a slender rachis; pinnules deeply dissected, 

 ultimate divisions narrowly linear, with bluntly terminated apices. 

 Venation of Sphenopteridis type. 



Under this species a few specimens are included which have a 

 certain amount of resemblance to the more finely-divided forms 

 of Ruffordia Gopperti (Dunk.), but differ in the much smaller 

 size of the ultimate segments, and in their more compact habit. 

 In the absence of any trace of fructification it will be better to 

 keep the provisional genus Sphenopteris. Compare the specimens 

 mentioned below with Figs. 5 and 6 (V. 2295 and V. 2731), 

 PL III. of Ruffordia Gopperti, also, as regards habit, with 

 Onychiopsis elongata (Geyler); 2 S. Fontainei suggests, to some 

 extent, the latter species in miniature. 



I have ventured to name this species after the author of the 

 " Potomac Flora," who has made such valuable contributions to 

 our knowledge of North American Mesozoic floras. 



V. 2155. PL VII. Fig. 2. 



Part of one side of a ? frond, with the details fairly well shown. 

 Ecclesbourne. Rufford Coll. 



V. 2152. More of the frond shown than in the former specimen, 

 but the details less distinct. Ecclesbourne. Rufford Coll. 



V. 2295. Two specimens very similar to V. 2155; also the 

 fragments V. 2154 and V. 2358. Ecclesbourne. Rufford Coll. 



1 Jahrb. k. preuss. Geol. Landesanst, 1889, p. 21. 



2 PI. II. Fig. 2. For more complete specimens refer to Yokoyama, Journ. 

 Coll. Sci. Japan, vol. iii. pi. ii. 



