Sir J. Lubbock on the Parallel Roads of Glen Roy. 547 



Sea only, 3 common to that sea and the Pacific Ocean, and 2 in the 

 Pacific Ocean and Red Sea, but not in the Caribbean. Twelve 

 other species are common to European deposits and the West-Indian 

 Miocene, 10 being of the same age in both hemispheres, while 2 

 occur in the Lower Chalk in Europe. These 23 species being de- 

 ducted from those of the West-Indian Miocene, a large charac- 

 teristic fauna still remains ; and Dr. Duncan showed that the recent 

 representatives of the characteristic genera composing it are for the 

 most part inhabitants of the Pacific and Indian Oceans, the Red Sea, 

 and the Australian waters, and that their Tertiary congeners are 

 found in Europe, Australia, Java, and Sinde. Of the 14 genera 

 thus enumerated, 8 are not represented in the recent coral-fauna of 

 the Caribbean Sea. 



Jamaica has yielded the only known Cretaceous and Eocene 

 corals ; and Dr. Duncan stated that the former are identical with 

 European Lower-Chalk species, and that the latter are similar to 

 species from the London Clay, the Bracklesham Beds, and the 

 Paris Basin. 



Dr. Duncan then mentioned several curious facts in the distribu- 

 tion of the West-Indian corals, both fossil and recent, and especially 

 the circumstance that whilst Jamaica, San Domingo, and Guada- 

 loupe present solitary species mixed with those indicating shallow 

 water and a reef, Antigua and Trinidad offer for consideration only 

 reef- species. In conclusion the author drew attention to the con- 

 firmation by subsequent discoveries of his theory of an Atlantic 

 archipelago, which he had put forward in his earlier papers. 



December 18, 1867.— Warington W. Smyth, M.A., F.R.S., 

 President, in the Chair. 



The following communications were read: — 



1. '* On the Parallel Roads of Glen Roy." By Sir J. Lubbock, 

 Bart., F.R.S., Pres. Ent. Soc. 



The author did not enter into the question as to the manner in 

 which the valleys were filled with water, but, assuming that the 

 "roads" or "shelves" represent ancient water-margins, he at- 

 tempted to point out the manner in which they were produced. 



The theory of Macculloch, which has been adopted by Darwin, 

 Lyell, and Jamieson, is, that the matter brought down by frost, 

 rain, &c. from above was arrested by the water, and heaped up by 

 the action of the waves. If this were the true explanation, however, 

 Sir John argued that the roads would form an excrescence on the 

 slope of the hill, which they do not, that their breadth must vary 

 considerably, that the slope of the roads would be towards the hill, 

 and that the roads would be widest where the inclination of the hill 

 is less than usual, and where streams bring down matter from above, 

 whereas, on the contrary, in these places the roads disappear. 



In opposition to this theory, Sir John then argued that the action 

 of the waves under such circumstances would be to throw matter 

 down, and not up. Given a slope of angular debris standing at the 

 angle of repose, partly in air and partly in water, the angle will be 



