4 
THE GEOLOGIST. 
That something like this has taken place seems indicated by the 
film-like character of such specimens of wood as those we have 
referred to, in which cases the sulphuret of iron was probably de- 
posited in the fine parting between the wood and the bark. More- 
over, the casts of the teredo-holes are covered over with the same 
film of red oxide of iron, which has resulted from the decomposition 
at a subsequent period of the sulphuret. 
Although we attempt not then to determine their family or genera, 
we are not doing bad service to science in drawing attention to these 
fossil cretaceous fruits. The very knowledge of their existence will 
stimulate other observers to seek for more illustrative examples. 
"What one is defective in, another may possess, and so from one to 
the other we may gain a general knowledge of the whole organism 
long before any perfect specimen has been brought to light. 
In the present case we submit our plates and figures of these 
fruits, and leave the honour of naming them open to him who can 
really tell us What they are. 
ON THE INAPPLICABILITY OF THE NEW TERM 
"DYAS" TO THE "PERMIAN" GROUP OF ROCKS, 
AS PROPOSED BY DR. GEINITZ. 
COiTMUNICATED BY 
SiE Roderick Impet MtrECHisoN, F.R.S., D.C.L., LL.D., etc., 
Director' General of the Geological Survey of Britain. 
In the year 1859, M. Marcou proposed to substitute the word 
"Dyas" for " Permian," and summed up his views by sayiug that he 
regarded " the New Red Sandstone, comprising the Dyas and Trias, 
as a great geologic period, equal in time and space to the Palaeozoic 
epoch or the Greywacke (Silurian and Devonian), the Carboniferous 
(Mountain-limestone and Coal), the Mesozoic (Jurassic and Creta- 
ceous), the Tertiary (Eocene, Miocene, and Pliocene), and the recent 
deposits (Quaternary and later)" ! ! * 
As that author, who had not been in Russia, criticized the labours 
and inductions of my associates De Yerneuil and Von Keyserling, and 
myself, in having proposed the word "Permian" for tracts in which 
he surmised that/ we had commingled with our Permian deposits 
much red rock of the age of the Trias, I briefly defended the views 
* See ' Dyas et Ti'ias de Marcou,' Bibliotheque Universelle de Geneve, 1859. 
