61 



rib conspicuous; secondary veins concealed in a somewhat 

 coriaceous integument. 



Although the fragment is very imperfect, the above 

 characters will serve to identify it, as it is very markedly 

 distinct from any other allied forms described as occurring in 

 Australia or Tasmania. 



Collected by the Eev. J. Button from the Mesozoic shales 

 ■of -Dunally. 



Pbcopteeis Caudata. (E. M. Johnston. Pig. 4.) 

 Pig. 4 is now referred by me to the above species. At 

 tot, owing to the more delicate structure and apparently 

 liner neuration, I was inclined to separate it from the above 

 species under the name Pecopteris tonsorius, but as this 

 small difference may be due to habitat or to the medium in 

 which it is preserved, I have thought it better to refer it for 

 the present to my original species (P. caudata). The figure 

 given is presented in natural size. 



Locality.— Altered shales near East Bay Neck, Tasman 

 -Peninsula, Tasmania. 



Collected by the Eev. J. Button, Dunally. 



Thinnfeldia Bu/toni. (Nov. sp. Pig. 18.) 

 Prond pinnatifid (? bi-pinnate) ; pinnas nearly opposite, 

 lanceolate, stromboido-lanceolate, falcate, accuminate; margin 

 simple ; the lower pinnae probablv shorter, giving ihe frond a 

 broadly lanciform appearance ; the upper side of base more 

 or less roundly constricted, nearly auricled ; the lower side 

 of base also more or less constricted, and almost decurrent, 

 giving the rhachis a faintly winged appearance; texture 

 very delicate; stalk, though somewhat broad, appears to be 

 thm flat, weak, and membranaceous, with a few fine longitu- 

 dinal stnse. Nerves, comparatively few, arising freely from 

 base, and ascending dichotomously, and laxly, at a hio-h 

 angle (nearly parallel) to margin, the central nerve reaching 

 apex, being only a little more prominent than the free lateral 

 series. All the nerves are extremely fine, and are almost 

 completely immersed in the delicate pachypteris-like tissue. 



Length of larger pinnae, about 1| inches ; greatest breadth, 

 about j inch. 



In form and general characteristics it comes very close to 

 Thinnfeldia indica, Pstm., of the Indian Eajmahal Group. 

 It differs from the latter, however, in having finer and more 

 delicate nerves, and a more delicate texture. The nerves 

 differ also in the manner in which the greater number spring 

 freely from base instead of acutely arising mainly from 

 central primary. The more or less parallel arrangement of 

 the nerves also distinguishes the species from its allied 

 Indian congener. 



