BUNBURY ON THE COAL FORMATION OF CAPE BRETON. 423 



The following letter from Mr. Sharpe has been received by Mr 

 Smith since the above paper was read : — 



" Adelphi Terrace, April 5, 1847. 

 " My dear Sir, 



*' In my last visit to Lisbon I found that the tertiary beds on the 

 two sides of the Tagus corresponded less exactly than I had before 

 supposed ; and I came to the conclusion, that although the whole of 

 the fossiliferous beds belong clearly to one formation, having many 

 species of shells common throughout, yet that the beds on the north 

 side of the river lie below the whole of those near Almada on the 

 south bank. 



" At the village of P090 do Bispo, a few miles above Lisbon on the 

 north side of the Tagus, a bed of enormous oysters {Ostrea gigantea 1) 

 makes its appearance on the beach, from whence it may be traced, 

 gradually receding from the river, to the back of Lisbon. This bed 

 is nowhere to be seen on the south of the Tagus, where it could not 

 have been overlooked : about twenty feet above the oysters lies a bed 

 full of univalve shells, which also has not been seen on the south 

 bank, and these beds are almost the uppermost on the north side. 

 Therefore as the base of this formation is seen on the north of the 

 river and the top of it on the south, we must add the two together to 

 obtain the whole thickness of the formation, which must be much 

 greater than I represented it in the account of the geology of Lisbon, 

 printed in our * Transactions.' 



" Believe me, 



a Very truly yours, 



" To J. Smith, Esq.'' " Daniel Sharpe." 



On Fossil Plants from the Coal Formation 0/ Cape Breton. By 

 C. J. F. BuNBURY, Esq., F.G.S. 



Since Mr. Lyell gave, in his * Travels in North America,' a catalogue 

 of the fossil plants occurring in the coal formation of Nova Scotia, I 

 have received, through the kindness of Richard Brown, Esq., a fine 

 collection from the Sydney coal-field. Cape Breton, including many 

 species which are not in Mr. Lyell' s list, and some which appear to 

 be altogether new. As this collection also enables me to illustrate 

 more satisfactorily the structure of some species which have hitherto 

 been incompletely described, I have thought it might be worth while 

 to lay before the Society some account of it, together with a few 

 remarks on the geographical distribution of these extinct plants. 



1. Neuropteris cordata, Brongn. 



This appears to be the most common Fern in the Sydney coal-field : 

 most of the slabs of shale which I have seen from that locality con- 

 tain fragments of it. The leaflets almost always occur separately, 

 very seldom attached to the stalk, and they vary to an extraordinary 

 degree both in shape and size, so that this species might deserve the 

 name of heterophylla quite as much as the plant to which it has been 

 applied. 



