BONNE Y : ON THE ORIGIN OF THE BRITISH TRIAS. 13 
highly suggestive of incipient salt-lake conditions, where the 
level of the water is liable to rhythmic oscillation. That the 
Red Marl was an inland sea deposit is, I think, now generally 
admitted, and confirmation is found, if that were needed, by 
Professor Watts' remarkable discovery of sand-worn rock sur- 
faces at Charnwood and Mr. T. 0. Bosworth's finding of " millet 
seed " grains, both in the intercalated sandstone and even, 
as he has recently informed me, in the marl itself in more than 
one part of Leicestershire. In regard to the former, I may say 
that I now think it probable that a slight planing off of the 
surface ridges of rock at Charnwood and near Narborough, which 
formerly I thought might be due to grounding ice, may really 
have been the effect of sand-drift. Mr. Strahan also has called 
attention to the fact that the paucity of organic remains in 
the Keuper is suggestive of desert conditions,* and the evidence 
collected in the Reports published by the Association after the 
last three meetings points in the same direction. But I think 
that the Red Marl as a whole is an aqueous rather than an aerial 
deposit, or in other words that it differs from the rest of the 
great Mesozoic clays only in being formed in an inland sea in- 
stead of in one communicating with the ocean. The frequent 
shore breccias, especially in the south of England, as I stated 
in my paperf on the relation of such deposits to the physical 
geography of their age, suggest a climate rather liable to ex- 
tremes and not improbably arid, something Hke that of Persia, 
or perhaps even Eastern Turkestan at the present day, and 
such a climate may very well have continued from the beginning 
of the Permian, with its important breccias of Rothliegende 
age, to the end of the Keuper, when the sea again invaded the 
British lowlands, over which it ebbed and flowed till almost 
Mid-tertiary ages. How far this episode of a marked Con- 
tinental cUmate was due to a combination of Caledonian and 
Armorican foldings is an inquiry into which, though full of 
interest, time forbids me to enter. Enough to say that, if a 
mountain chain, capable of feeding rivers, comparable with 
those which now issue from the Alps, were situated anywhere 
* Geol. Survey Memoirs, South Wales Coal-field (Bridgend), 
t Quart. Joum. Geol. Soc, Iviii. (1902), p. 185. 
