Vol. 59.] SOUTH DEVON AND THE MIDLANDS. 317 



red or purple, and the entire, or almost entire, absence of many 

 important rock-groups. As in the Midlands, there is a small 

 proportion of tourmaline-grit and quartz-felspar grit. 

 Prof. Bonney also states that both deposits 



1 contain some felstones, with more basic rocks of compact structure and 

 purplish colour ; also granitoid rocks in a very rotten condition.' ] 



It would indeed be difficult to describe the deposit in general terms 

 which would not equally apply to the Bunter Conglomerate of the 

 Midlands. 2 



Judging only from lithological evidence, the bulk of the pebbles 

 must have come from a definite region of a comparatively simple 

 geological character. The palseontological evidence also, as origi- 

 nally stated by Salter, confirms this, and, by showing that the 

 Ordovician fossils, at least, are of Norman types, points definitely 

 to a southern source. This is in accordance with the evidence of 

 the Pebble-Bed itself, which appears to have been thicker in the 

 part which has been removed by the sea, and, as Mr. Ussher 

 has shown, 3 seems to die out in a northerly direction, so that at 

 Burlescombe only small quartz- and grit-pebbles were found. 



The large number of Devonian brachiopoda occurring in the 

 Budleigh-Salterton pebbles may possibly have induced Davidson to 

 favour on the whole the ' mid-Channel ' hypothesis, although he 

 admits that the pebbles, or many of them, may have come from 

 France. But, apart from the question whether the number of 

 Devonian fossils affords any index to the proportion which the 

 Devonian pebbles bear to the whole, the fact must be borne in 

 mind that, with the exception of Spirifera Verneuilii and Sp. 

 speciom, the whole of the list given by Davidson consists of species 

 which do not occur in situ anywhere in Britain. Since they are 

 non-British types, it is surely not necessary to look as near to 

 the British area as possible for their original source. 



And we have another fact to guide us. The pebbles at Budleigh 

 Salterton which contain Devonian fossils are associated with others 

 which contain Ordovician fossils, and these are all, or almost all, 

 identical with Norman forms. Now, the old Ordovician land of 

 Normandy must at one time have had other ancient rocks super- 

 imposed upon it. There are still in the Calvados fragments of 

 Silurian and Carboniferous brought in by faults, and the Devonian 

 is represented in parts of Normandy and Britanny. What sup- 

 position, then, is more natural than that the Devonian was once 

 represented either in the Calvados district, or in some region in the 

 same drainage-area as that which has supplied the Ordovician 

 element of the Budleigh-Salterton pebbles ? 



The claim, therefore, that Normandy (or some land anciently 

 connected therewith) was the source from which the pebbles were 

 originally derived, is so strong that it demands a special examination. 



But, in fact, no other source has been seriously advocated ; for 



1 Geol. Mag. 1895, p. 76. 



2 See T. G. Bonney, ibid. 1880, p. 404. 



3 Quart. Journ. Geol. Soc. vol. xxxii (1876) p. 367. 



