230 



NILSSONIA. 



3. Nilssonia tenuinervis, Nathorst. 



[Berattelse, p. 35, 1880.] 



(Text-fig. 41.) 



1880. Niksonia tenuinervis, Nathorst, Berattelse, p. 35. 

 1894. ? Ifdssonia 2}olymorpha, Bartliolm, Bot. Tidsskrift, pi. i. figs. 5, 6. 

 1900. Mlssonia tenuinervis, Seivard, Manchester Lit. & Phil. Soc. vol. xliv> 

 p. 4. 



Frond linear ; the lamina entire, ctaracterized by the numerous 

 fine veins given off almost at right angles from the axis. 



Nathorst proposed the specific name tenuinervis for a fcTV examples 

 of Nilssonia fronds from the Inferior Oolite of the Yorkshire 



i.. 



1 = 



f 





-- in ^- 



:-'.^:*f 



■ - H 



Fig. 41. — Nihsonia teiiiiinen'is, Nathorst. No. 13,502. (Nat. size.) 



coast, -which differ fi-om the other species of the genus in the 

 greater number and fineness of the lateral veins ; he notices 

 the resemblance which the species bears to the genus Tceniopteris. 

 Nathorst's species may be compared with Ifilssonia oricntalis, Heer.' 

 Nathorst's species appears to be represented bj' three specimens 

 in the National Collection and bj" a few others in the Museums of 

 Manchester and other places. 



> Heer (78"-J, pi. iv. figs. 4-9 ; Nathor-st (97), pi. i. fig. 18. 



