Memoir of the Rev. Thomas Brown. 343 



shore, caught his attention, Ichthyolite, molluscan, and 

 crustacean remains were found in it, and as some of these 

 were well known Irish forms, they raised the question, may 

 not this bed of Limestone synchronise with the Irish series 

 in which these forms occur? Mr Brown felt he had broken 

 new ground here, because neither Maclaren, nor Landale, nor 

 Anderson, who had worked much in the neighbourhood, had 

 referred to it. He resolved, in the face of many difficulties, 

 to work it out, and for several years devoted his autumn 

 leisure to this. He succeeded, both from the strati graphical 

 and palseontological points of view. 



1863. — "On a Clay deposit, with Fossil Arctic Shells, 

 recently observed in the Basin of the Forth." This bed of 

 Clay was discovered, and the attention of geologists first 

 called to it by Mr Brown. It was specially interesting to 

 him at the time, as, he thought, indicating the former 

 existence in Scotland of an Arctic climate — the shells found 

 in it being, for the most part, exclusively Arctic, and several 

 of them new to British Glacial deposits. He believed, 

 moreover, that the stratigraphical position of this bed 

 warranted the inference of a considerable rise throughout 

 the whole sea- board of the Forth. 



1864. — "Notice of Glacial Clay, with Arctic Shells, near 

 Errol on the Tay." The shells in the Errol brick clay were 

 found to be identical with those at Elie. The area within 

 which these shells occur thus became greatly enlarged, and, 

 as he thought, it also favoured his theory touching the rise 

 of the land. 



1874. — "On the Parallel Eoads of Glenroy," Lochaber. 

 The subject has proved a tempting one to students of 

 Quaternary deposits. The theories of their formation were 

 mainly three; (1) the Maculloch — Dick-Lauder — Milne-Home 

 theory, — the glen once the site of a lake. (2) The Darwin — 

 Nicol, R. Chambers theory, — the terraces mark the level of 

 an arm of the sea at three different periods; and (3) the 

 Agassiz — Buckland — (Mr) Jamieson theory, — glacier lake, the 

 glacier, melting at three widely separated periods, left the 

 marks of this in the terraces. 



Dr Brown approached the problem from a new, the biotic, 

 point of view. That the deposits contain no shells was 

 accounted for by Darwin, who alleged that the carbonic acid gas 



