114 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
plains. At the upper end they are mostly composed of large fragments, 
the interstices filled with gravel and sand, but farther from the hills 
the larger fragments for the most part are left behind and the general 
texture of the deposits is finer. The pebbles even to the outermost 
limit generally remain imperfectly rounded, for when streams flow 
after a rain they are generally so loaded with debris as to be of the 
nature of fluid mud rather than water and in this the fragments of 
rock seem to be carried en masse without being worn against each 
other to the same extent as in a mountain torrent....Another effect 
of the large proportion of mud and stones moved is that occasional 
large blocks travel in the moving mass far beyond where their fellows 
are left behind. Occasional exceptional floods bring down larger 
blocks than usual, which afterwards are covered by or embedded in 
material of smaller grain.” 
:— Europe; Great Britain. In the Upper Old Red Sandstone 
there are thick accumulations of subangular conglomerate or breccia 
that recall some glacial deposits of modern times. The stones in the 
conglomerate are usually well rounded even when one foot in diameter. 
The larger blocks are usually more angular fragments locally derived. 
The smaller rounded stones have often come from a distance; at least 
it is impossible to discover any near source for them (A. Geikie, p- 
1001). It was thought by Ramsey that the deposits were of glacial 
origin and his reasons for ascribing them to such a source are given 
later. It has, however, since been shown by W. Wickham King, 
Oldham, and others that they are the product of fluviatile action and 
that glacierstwere only indirectly, if at all, concerned in their formation. 
According to Ramsey the deposits consist of stones embedded in a 
deep red, marly paste. The stones are mostly angular or subangular 
with flattened sides and but slightly rounded edges. In one locality 
none of the fragments exceed six or eight inches in diameter. There 
are in the immediate neighborhood no rocks answering to a majority 
of these. He infers, therefore, that some, at least, have travelled 
twenty or thirty miles (Ramsey, p. 189). At another place the sides 
of some of the pebbles are not only flattened but are sometimes polished 
and occasionally scratched (ibid., p. 190). At a third locality the 
rock is a rudely stratified breccia with some fragments as much as 
two or three feet in diameter (ibid., p. 194). The area covered is 
estimated at 500 square miles. Later work in more recently opened 
quarries at several of the localities noted by Ramsey has been con- 
ducted by King, who has shown that Ramsey’s argument for a distant 
source of materials no longer holds. The deposit is rudely stratified 
