JURASSIC PLANTS FROM KAGA, HIDA, AND ECHIZEN. 



41 



Nilssonia orientalis-Heer, Beitr. z. Juraflora Ostsib, n. d. Amurl., 

 1878, p. 18, pi. IV, fig. 5-9. 



Specimens of a Nilssonia represented in the above cited figures 

 are, I believe, to be identified with what was described by Heer as 

 N. orientalis from Ajakit on the Lena in Siberia. Our specimens are 

 all entire-margined, which though variable in form, always possess a 

 truncated apex. Fig. 5, though broken, shows an entire leaf which 

 is about 23 mm. broad and only 44 mm. long ; so it is tolerably short. 

 Fig. 4 represents a large leaf, 25 mm. broad with 46 mm. of the length 

 preserved ; therefore it is probably a much longer leaf than the above. 

 In all of our specimens the veins, which are curved and directed 

 forward, are densely crowded, occurring as many as four to the 

 millimetre, and thus exactly agreeing in venation with the Siberian 

 specimens. 



Every one of our specimens shows a strong convexity on the 

 upper surface of the leaf, and a sharp edge on the rhachis where 

 the blades meet from both sides. Sometimes a leaf is found quite 

 doubled over. 



Heer compares this species to A", pohjmorplia Schenk of the 

 lihaetic flora of the Franconia and Sweden, the entire forms of 

 which indeed the Japanese leaves in some cases resemble. \ et a 

 decidedly denser state of veins distinguishes the latter from the 

 Rhaetic species. 



According to the investigations of Prof. Nathorst, this species 

 also occurs in the Oolite of Yorkshire. 



Very numerous at Halcof/ase, though mostly fragmentary, and 

 forming there the most abundant fossil. 



25. Nilssonia ozoana m. 

 PI. X, fig. 2b, 11-14. 



