BY THE REV. J. E. TENISON- WOODS, F.G.S., F.L.S. Ill 



Alethopteris, Sternberg (as limited by Schimper.) 



Frond bi- or tri-pinnate. Pinnules coriaceous, simple, often 

 quite entire, base wide, decurrent, free or simple, margin 

 renexed or re volute (covering sori Vj Costa, immersed in a 

 groove above, but prominent behind ; veins, prominent or flat, 

 simple or forking once, the venules diverging and reaching the 

 margin. 



The genus which comes nearest to this amongst existing forms, 

 is the common Pteris or Brake, excluding those species which 

 have a reticulate venation ( Lonchopteris) . Schimper is of opinion, 

 that it is impossible to establish any clear line of demarcation 

 between Alethojiteris and Pecopteris> though they form characteristic 

 groups sufficiently distinct.* 



Aletho-pteris australis, Morris (in Strzelecki as Pecojiteris, p. 248, 

 PL viii , fig. 1, 2, 2 a.). Frond bi-pinnate, pinnae oblique, alternate, 

 rather distant ; pinnules thin, falcate, and rather obtuse, oblique 

 and somewhat incurved, more or less adnate to the rachis, and 

 sometimes decurrent, dilate at the base or auriculate Costa, slightly 

 flexuous, evanescing towards the apex, veins oblique, bifurcate or 

 dichotomous. Obs. This fern belongs to the Neuropteroid division 

 of Pecopteris and bears much greater resemblance to the P. whit- 

 biensis and P. tenuis of the Oolitic series of England, than to any 

 other species described by Brongniart as occurring in the coal 

 measures. The frond appears to have been bi-pinnate with oblique 

 alternate pinna?, the pinnules thin, somewhat falcate and obtuse, 

 the margins of which vary slightly in form; being either sinuous 

 or entire, according to their position on the frond. This fossil 

 bears considerable analogy to the Pecopteris lindleyana, figured in 

 Professor Boyle's illustrations. 



* Feistmantel in his papers in the Indian Geological Survey, says that this 

 genus is especially distinguished by having the pinn* inserted in the stem 

 by their whole base, and by their basal portions being generally joined 

 together. See Foss. Flora. Gondwana, vol. 2, p. 22. I am afraid however, 

 that in some species, variability may be seen in this particular. But the 

 generic distinction is of value, because the genus Pecopteris would be so large 

 and unwieldy without it. 



