204 J. H. A. Whealler—Boulders of Cambridge Gravels. 
a dyke rock of Old Red Sandstone age. It has lately been collected 
several times at the Travellers’ Rest Pit, and can be easily recognized 
by the weathering out of the quartz grains on the “ boulder surface ” 
as black specks. 
Cheviot rocks are common and call for no further notice, except 
that many types are found, including andesites, porphyrites, and 
porphyries. 
Several boulders have been collected of the Old Red Sandstone, 
which must be erratics from either the outcrop at the Border or from 
that north of the Firth of Forth. 
One of the basalts collected at the pit was sliced, and both the 
boulder and the slice were submitted to Mr. HE. B. Bailey, of the 
Geological Survey of Scotland. He stated that this specimen was 
a basalt of the Dalmeny type, approaching in its richness in augite 
phenocrysts and poorness in felspar in the groundmass to the 
Hillhouse type, and would be matched exactly under par. 6, p. 106, 
E. Lothian Memoir (1910). 
With regard to the presence of Lake District rocks in this district, 
more and more evidence is being collected in favour. At the time 
of publication of Rastall and Romanes’ paper the finds were as 
follows :— 
ee granite porphyry \Kings Horn Thales 
Andesite with old label: “* Drift, Cambridge ”’. 
Andesite with old label: “‘ Observatory, Cambridge”. 
All these andesites are remarkably similar to the andesites of 
the Borrowdale series. They are well-preserved, compact, dark- 
green rocks, in which are embedded small laths of felspar. Since 
then two more specimens have been collected, one in 1909, after 
the publication of the paper by Rastall and Romanes, at the Milton 
Road Pit, and one last year at the Travellers’ Rest. Thus five 
similar’ specimens have been found, all bearing very strong 
resemblance to the Borrowdale lavas. 
The muscovite granite porphyry confirms the other specimens, as 
it is identical with the Dufton Pike rock. 
The cumulative evidence of these types really forces one to the 
conclusion that Lake District rocks have been transported to the 
Cambridge area. 
With regard to class 4, the north-eastern and eastern English 
rocks, the following have been found :— 
Millstone Grit. 
Coal-measure sandstone. 
Carboniferous limestone. 
Jurassic “‘ oyster bed ”’. 
Several other sandstones (common). ° 
Porosphere. 
? Red Chalk. 
