94 SURVEY UNDER OFFICE OF WORKS CHAP, in 



put you in possession of things as I know them, since, as matters 

 stand, you will not get them elsewhere. 



First to clear the ground as to classification. If the older 

 rocks be classed, as they are, according to the remains of life found 

 in them, it follows that any given mass of them containing the same 

 kind of life, really and truly, should have but one name. Whatever 

 the Bala beds may turn out to be, as to equivalent deposits in 

 geological time, they present, so Forbes says, the same kind of life 

 as that contained in the Silurian system, according to your published 

 works. The consequence of general name follows that is, one 

 name for the whole. 



Next come the beds, which have been termed the Lingula beds 

 these underlie the others. Whatever other fossils may be found 

 among them in Wales, our collection will ultimately show. In the 

 meantime, rocks in Ireland which may be equivalent both to these 

 and the Bala beds contain Silurian fossils. Supposing further 

 researches to confirm these views the same kind of life still, with 

 its consequences about one name. 



Beneath these come rocks which you know well at the Long- 

 mynd, and of which you showed me an old section, at least one 

 showing your views at the time respecting them. 



Without aid of any kind Ramsay this year made out their story. 

 Of the equivalents near St. David's you have often heard me speak, 

 and touching the Irish rocks of the same date you know what I said 

 the other night. Of all the exhibitions of them the Irish is the best 

 a great thickness. Now it has been supposed that these beds are 

 not fossiliferous. This is not true in Ireland. Two or three years 

 since Oldham got some things that were clearly organic, though in 

 such a condition that nothing could be made of them. But this 

 year one of our lynx-eyed collectors has been turning out good 

 specimens. What they are is not clear ; anyhow they are more 

 diffused than at first thought. Now with this group of rocks 

 classification is not clear. We have abundant evidence, capital in 

 Ireland, of their slow deposit through a long lapse of time. These 

 things I tell you in confidence, because the affair is incomplete, and 

 there is much yet to be done, but you should know them and now 

 I must run for it. Ever sincerely, H. T. DE LA BECHE. 



Griffith, in a document he has sent in to us of about a year's 

 date, has got there older rocks, though not correctly mapped. He 

 calls them Cambrian, and whenever he publishes his new edition of 

 map, so they will, I suppose, be called. 



Before the end of the season for field-work in the 

 year 1846 Ramsay received an invitation which 



