ö ART. 5. — M. YOKOYAMa. 



6. PODOZAMITES LANCEOLATUS (Lindl. et Hutt.) 



PL I. Fig. 6. 



Podozamites lanceolntus Yokoyama, On Some Fossil Plants 

 from the Goal-bearing Series of Nagato, -p. 245, p/. XXXIV^ fig. 

 3, 4. 



Podozamites distans Zeiller, Flore Foss. d. Gîtes d. Cfiarb. 

 d. Tonkin, p. 159, pi. XLTI, fig. 1-4. Nathorst, Beitr. z. foss. 

 Flora Schwedens, p. 23, pi XIII, fig. 1-6, XV, 20. 



Zamites distans Schenk, Flora der Grenzschichten, pi. XXXV, 

 fig. 10, XXX VI. 



Specimens belonging to this well known form of Podozamites 

 are quite frequent at Yamanoi, though mostly in a fragmentary- 

 state. The one shown in our figure has the leaflets attached to 

 the rachis. Judging from their shape, the plant seems to belong 

 to the variety genuina of Heer. 



Zeiller is of opinion that the Rhsetic Podozamites distans 

 (Presl) should be kept separate from P. lanceolatus (Lindl.) of 

 the Middle Jurassic, on the ground that they belong to two dif- 

 ferent geological horizons. Indeed it is quite true that, similar 

 as they are, they may possibly be two different species. But in a 

 case like this, in which the determination must be based upon the 

 leaves alone in which the two species present no marked differen- 

 ces, their union is not at all unjustifiable, especially when we 

 consider that some of the plant fossils are remarkable for their 

 longevity. One instance of this is found in our Onychiopsis 

 elongata (Geyl.) which is not only abundant in our Lower Oolite, 

 but also in our Neocomian. Recently it has even been suspected 

 that it occurs also in the Lias. 



