CORRESPONDENCE. 



363 



ther more likely that the shales represent intermediate and different 

 conditions happening between each formation of coal ; and, in this 

 case, the ferns imbedded in the shales may have belonged to quite 

 another- class of vegetation from that which formed the coal. Has 

 anybody ever thought sufficiently how far the tender herbs of those 

 days and myriads of fallen seeds might have been the chief sources 

 of that bituminous product which makes England the first country 

 in the world for civilization and wealth ? 



It is not our intention now to enter, however, into the matter of 

 the formation of coal, nor of the nature and characters of the many 

 beautiful vegetable forms which are imbedded in the intercalating 

 strata. But we wish some one would earnestly take up the work. 



COKBESPOKDENCE. 



The Older Parian in Trinidad. 



Dear Sie, — Permit me to observe, in reply to Mr. Lankester (whose 

 letter appeared in your issue of July), that I am not the authority for the 

 correlation of the Older Parian formation in South America and Trinidad, 

 with the Neocomian of Europe. Indeed, from the references I gave 

 I should have thought that Mr. Lankester would have had no great diffi- 

 culty in finding out that the supposed age of the formation in question 

 rested upon far better evidence than any I could produce. I had it only 

 in my power to add a little to the evidence already accumulated on the 

 subject, and to demonstrate it almost to a certainty that the rocks at 

 Pointe-a-Pierre in Trinidad do belong to the same formation which it was 

 the opinion of the Government Geological Survey that they did ; that is, 

 to the formation at Cumana, containing Trigoviia subcrenulata. The opinion 

 of the Government geologists was built upon evidence which was none the 

 worse for being strengthened ; and I had it in my power to do so. 



But if the references given in the footnotes to my paper are not suffi- 

 cient. I beg to refer Mr. Lankester to those appended to Mr. Wall's paper 

 on the geology of Venezuela and Trinidad (Quart. Journ. Geol. Soc, 

 vol. xvi. p. 465). Von Buch's work on the fossils collected by Humboldt 

 contains much evidence relating to the age of the formation in South 

 America. 



When I transmitted my paper to you I was perfectly aware of Professor 

 Huxley's views as regards " homo taxis ; " and I have held opinions of 

 a somewhat similar kind for some time previously to reading Professor 

 Huxley's able address to the Geological Society. But in writing my 

 paper on the Older Parian formation, my object was not to support or 

 elucidate any theory which is yet quite new and unacknowledged by 

 geologists at large ; more especially when it did not make the least differ- 

 ence one way or the other as to the question upon which I was engaged. 

 Whether- the rocks in South America containing organic remains of types 



