and, last of all, the lull open sea. It was the work of ages. 



The Rhrj^tic beds, — which owe their name to the Alps of 

 Lonibardy, (the ancient ri^hcx'tia,) the Orisons, and the Tyrol, 

 v.'here they attain a considerable thickness, — had not been found 

 further to the north in England, in 1866, than at Coptheath 

 near Birmingham, and at Abbots Bromley in Staffordshire; when, 

 in that year, as the gradients of the line between Gainsborough 

 and Lincoln were lowered, I had the satisfacticm of meeting 

 with them. Since that time they have been discovered, in a 

 nearly continuous line, across England from north to south, 

 wherever the junction of the Trias and Lias is exposed. 



Some geologists place tiicsc beds at the top of the Trias, 

 others at the base of the Lias, or Jurassic system. This, iiow- 

 ever, is a matter of small impcnlance. They are the passage 

 beds from one great S3'stem to another, from the deposits of 

 the upper Keuper lake to those of the great Liassic sea ; beds 

 which go far to unlock the hidden stor\- of the land we are 

 considering. 



About the origin of the bone licds referred to mucli 

 speculation has taken phice. 



Mr. Jukes Browne, in liis work on " the Buildmg of the 

 British Isles," — to which I am indebted for several of the fact 

 stated in my paper, — speaks of the irruption of the sea watc 

 being prejudicial to the inhabitants of the Triassic lake, '' s 

 that most of them died, and their bones, scales and teeth wer 

 drifted into layers on the sea f^oor ; " but this I think coul ■ 

 hardl)' have been the case, as, apparently, the concentrated 

 saltness of the lake had, to a great extent, prevented the 

 possibility of life, — no trace ol it, except in a few' localities, 

 being met with throughout the system, — and this view- Mr. Jukes 

 Browne himself bears out, when, in another part ol his work, 



