36 M. YOKOYAMA. 



Fig. 8 and 10, both exhibiting crènate pinnae, probably be- 

 long to the same species. The latter figure represents a rather in- 

 distinct specimen. It shows, however, a primary rhachis which, 

 when compared with that of the second order, may be called pretty 

 strono-. It is by no means weaker than that of an English specimen 

 fio-üred li y Lindley, as the latter might represent apart of a frond 

 lvinsr lower in position than our own. 



Venation is indistinct, save a median vein which is in most cases 

 very clearly seen. It is comparatively delicate, disappearing near the 

 apex of the pinnules (fig. 9a). 



What Dr. Gey 1er described as Pecopteris exiliformis from the 

 Tetorigawa-valley is, I dare say, no other than the present species, 

 lie considers his plant to be more slender in general appearance than the 

 Scarborough species; but his figures as well as my own only show 

 the upper parts of primary pinnae, while conversely the figure of 

 Lindley represents only their lower parts. Be that as it may, after a 

 careful comparison between my specimens and Lindley 's figures, I 

 could find no character sufficient to separate the Japanese from the 

 English species. 



Btinbury observed in a pinnule of this fern capsules arranged in 

 a single row on each side of a midrib [Quart. Journ. Geol. Soc, 1851, 

 p. 188, pi. XJ J L fig. -mi, b), a fructification which he compares with 

 that of Aneimia and Mohria among Schizaeaceae. 



Rarely found at Shimamura. 



17. Pecopteris Saportana Heer. 



Pecopteris Saportana—Geylev, lieber foss. Pflanz, a. d. Juraform. 

 Japans, p. 22G. pi. XXX. fig. 1. Heer, Beitr. zur foss. Flora Spitzb., 

 p. 29, pi. VI, Jig. 4-7a, YJL 46. 



