OF THE SOUTH DEVON COAST. 15 
Two specimens from different parts of the Start headland call 
for no special remark. Three specimens, one from the schist to the 
west of Prawle village, the others from the two principal masses 
further west, selected to see if they were microscopically as well as 
macroscopically identical, agree in all essential particulars with one 
another and with the last two; so also do three from the Bolt Head, 
one from a quarry just inside the grounds, another from the eastern 
face of the Head, anda third from near the Mewstone, except that in 
these, perhaps, there may be a little more of the black mineral. 
There is therefore nothing to be discovered under the microscope 
which forbids us to consider all the thick masses of mica-schist one 
and the same rock. I figure a portion of one from the Bolt Head 
Fig. 7.—Section of Mica-schist fom the Bolt Head (x 50), 
(fig.7), to give an idea of the general structure and the extraordinary 
corrugations. I examined slices from the bands (A, and A, of fig. 2) 
which are undoubtedly below the main mass of the chloritic schist, in 
the hope of finding something that would characterize a lower mica- 
schist, but without success. They contain a few grains of a mineral 
which also occurs inthe chloritic schist, and rarely in the ordinary mica- 
schist; as I shall presently explain, this may be a felspar, but I have 
doubts as to its nature. I have also examined one of the lower 
schists from the northern side of South Sands, but it does not help 
in our attempts at differentiation. Hence, as might be expected, 
the microscopic evidence as to the position of the mica-schist is in- 
conclusive. 
The macroscopic aspect of the chloritic schist has already been 
described (p. 6). Seven specimens have been cut for microscopic 
examination. In these three minerals predominate :—(1) the most 
