436 
Proceedings of the Royal Society of Edinburgh. [Sess. 
leaf -trace of the type in question, it seems to us very improbable that it should 
have anything to do with the case of the Osmundacece. 
In conclusion, we wish to acknowledge our indebtedness to Mons. Th. 
Tschernyschew, the Director of the Geological Survey of Russia, and 
Mons. M. Zalessky, for the material of Thamnopteris on which our 
observations were made. 
(Issued separately August 12 , 1908 .) 
