2~)2 ON SOME FOSSIL PLANTS FROM DUBBO, N. S. WALES, 



TlIIXXFELDIA ODONTOPTEROIDES. Feistm. PI. IX., fig. 4. 



Refs.— Proc. Linn. Soc, N.S.W., Vol. VIII., p. 1C2. 



This fossil plant has been described and figured in almost every 

 variety by Dr. O. Feistmantel in the work already referred to. 

 As Feistmantel's papers are not easily procurable, and as Thinn- 

 feldia is (in Australia) a recognised characteristic mesozoic fossil, 

 I herewith present a figure of a specimen, from Garensey's Quarry, 

 Dubbo, where it is very common. It is confined to a particular 

 bed — a sparsely micaceous, finely bedded, friable sandstone. It 

 occurs, either in the shape of sharply defined casts, which show 

 Thinnfeldia to have been a plant with stout coriaceous pinnules, 

 or as a red impression (peroxide of iron), which is reduced to 

 dust by exposure. 



In a shaft sunk on the Railway, about three miles from the 

 Quarry, Thinnfeldia fossils are found in a remarkable state of 

 preservation, in a black carbonaceous shale. The shale may be 

 truly described as consisting almost entirely of plant remains. As 

 the shale is taken out fresh it is not easy to see the fossils, but as 

 the stone weathers they peel off in flakes. It is only necessary to 

 steep them in water, and pinnule separates from pinnule and rachis 

 from rachis so perfectly, that they may be mounted on microscopic 

 slides as translucent objects. Many of them can readily be used 

 as negatives to obtain nature-printed heliotypes. PL IX., fig. 4, 

 is an enlarged copy of one. 



Some of the pinnules are studded with minute dots, which may 

 be stomata. Although I have examined more than 50 specimens 

 by transmitted light, I have never met with anything which could 

 be considered as pointing to the mode of fructification, of which 

 nothing is known That this should be so, is remarkable, notwith- 

 standing all that has been written, and the great number of plants 

 that have been examined during the last forty years. It lends 

 some weight to the opinions of Ettingshausen and Andrea, who 

 placed Thinnfeldia with the Conifers. It is not easy to see the 

 reason for this, for it appears amongst ourselves co be a settled 

 question, that Thinnfeldia was a fern. 1 have to add the 



