94 W. Pengelly on the Red Sandstones, 
been correspondingly deeper than at present ; hence it appears that 
the submarine vallev separating England from France commenced 
its existence in post-Triassic times. 
As was previously stated, the rocks of the extreme south of 
Devonshire are crystalline schists ; rocks of the same general 
character occur at the Lizard, the southernmost point of Cornwall ; 
and the famous Eddystone rock, lying almost in the right line joining 
the two districts just named, is another variety of the same series ; 
they are all highly metamorphosed formations, that is to say they 
are, according to modern geology, ordinary stratified detrital accu- 
mulations which have been so transformed as not only to have 
acquired a crystalline structure, but, with the exception of their 
stratification, to have lost all indications of their mechanical sedi- 
mentary origin. There is little or no doubt that these Devonshire 
and Cornish schists, at least as such, are contemporaries ; their 
exact geological age, however, has long been considered to be pro- 
blematical. It has been the common, though not invariable, 
practice to regard them as the oldest rocks in the two counties ; but 
this, though probably the truth, has had no better basis than the 
doctrine, now exploded, that the first formed strata were crystalline, 
and vice versa. I incline to the opinion that the quartzite pebbles 
of Budleigh Salterton may be found to have suggested the solu- 
tion of this problem. Quartzite belongs to the series of metamor- 
phic rocks, but the change it has undergone is generally much less 
marked than that of the crystalline schists ; in the case before us 
even the fossils are far from being obliterated. 
That both the quartzites and the schists had undergone their 
metamorphosis prior to the Triassic era is proved by the facts that 
the *• pebble bed " so frequently mentioned consists almost en- 
tirely of fragments of the former, and that the well-known Triassic 
outlier at Thurlestone in Bigbury Bay is very largely, if not exclu- 
sively, composed of the debris of the latter. 
Briefly, then, the facts are these. 1st — An axis of highly me- 
tamorphosed rocks runs nearly east and west from the Start to the 
