92 Correspondence — Dr. 0. Feistmantel. 



without it. Whether we are to consider that Coral growth began 

 earlier in England than in Prance, or that Cidaris florigemma reached 

 lis later, is an interesting question; but this much is certain, that the 

 Coral growths continued to a much later period in Eastern France ; 

 hence the idea that Cidaris florigemma is indicative of a low 

 Corallian horizon. In the discussion on our paper, Professor Morris 

 pointed out that " the so-called Corallian occupied different zones in 

 different localities on the Continent, stretching, in fact, from the 

 Oxfordian to the Portlandian inclusive." Correlation, to be of any 

 value, therefore, is only to be effected by a detailed examination of 

 both the English and continental areas, without confounding to- 

 gether either the beds of different districts, or those of the same 

 district, as is generally done in all works dealing with the subject. 



London, Bee. 6, 1877. BlAKE AND HuDLESTON. 



P.S. The great stretch of country passed under review in the 

 " Corallian Rocks of England" obliged us to condense lists of fossils 

 as much as possible. Had we given a full list of fossils from the 

 North Pit, it is difficult to see that any doubt as to its age could 

 exist. The following, omitting certain indefinite forms, is as full a 

 list as we have been able to put together : 



Ammonites perarmatus Isocardia (cast) 



,, plicatilis Fygaster umbrella 



Littorina miiricata (var.) JSchinobrissus scutatus 



Pleurotomaria (cast) Holectypus depressiis 



GervilUa aviciiloides CoUyrites bieordatus 

 Opts Fhillipsi 



Only three of these occur in the South Pit. B. & H. 



CYCADACEOUS PLANTS OF THE DAMUDAS. 



Sir, — I beg you will allow me space to correct some erroneous 

 impressions that might be made by certain not sufficiently explained 

 statements published by me in the Geological Magazine, and 

 elsewhere, and to apologize to the gentlemen whom I thereby 

 have had the misfortune to offend. I beg to state that any such 

 effect was as far from my intention as it certainly would be contrary 

 to my interests, and I regret that, when stating facts, I did not 

 more fully notice circumstances that would only be known to those 

 immediately concerned. 



The following instances will sufficiently explain this unfortunate 

 misunderstanding. 



When writing in the Geological Magazine in November, 1876, 

 p. 489, on the occurrence of Cycadeaceous plants in the Damudas, 

 saying in footnote No. 10 "that they were known long ago," I ought 

 to have explained that the two species (out of three) I mentioned, 

 i.e. Noggerathia, near Vogesiaca and Glossozamites, although collected 

 some years since, have not before been determined as such, and only 

 Noggerathia ? Hislopi was by its describer (Sir Ch. Bunbury) con- 

 sidered as doubtfully Cycadeaceous, and I see now that my footnote, 

 No. 10, should have been written thus : " that Cycadeaceous plants 



