140 DREDGINGS OF THE MAklNE BIOLOGICAL ASSOCIAtlON : 



356/2. 3 miles S.S.E. i E. from Prawle Point. 



A silvery grey chlorite schist with minutely wrinkled surfaces of 

 chlorite precisely like the shore rocks. Much chlorite. 



These last three specimens are practically identical with rocks to be 

 found in situ on shore in the Start Point to Bolt Tail district. None 

 of the specimens show signs of travel or wear. 



M. 62a. S. 25° W. Edd., 46-4 miles. 



A mixture of felspar and quartz, largely the former. Micro-mylonitic 

 structure well developed and some of the felspars greatly deformed. 

 One in especial, with well-marked plagioclase twinning, is much bent 

 in reverse directions, is cracked, and finally at each end passes into 

 mylonite. The slide is full of similar evidence of deformation. As 

 a whole the felspar has a reddish tinge ; some portions are crowded 

 with microlites of high double refraction, probably calcite. Calcite is 

 rather freely developed, filling interspaces and cracks. Chlorite plays 

 a similar part, and the two are associated. In places the chlorite is 

 thickly strewn with minute grains and blades of a feebly translucent 

 brown mineral. 



If the presence of original felspars is to be the criterion this rock 

 should have been included among the gneisses. (Plate YII, fig. 2.) 



HORNBLENDE SCHISTS WITH AUGITE. 

 356/4/b. W. i S. Bolt Head, 4| miles. 



A very compact dark greenish-grey schist with occasional small 

 specks of pyrites. 



The slide looks distinctly patchy, augite areas of brown tint, and 

 granular augite. Much uralitic hornblende, blue in ordinary light, 

 with a faint tinge of green, pleochroism brownish grey to blue-green. 

 This mineral dominates the section. Much calcite, with a tendency to 

 form broad bands. And, filling irregular interspaces, a mosaic of water- 

 clear granules, containing both felspar and quartz. Calcite mingles 

 with this mosaic. A little leucoxene occurs. 



M. 80b. S. 16i° W. Edd., 48-9 miles. 



Fine-grained dark grey rock ; some pyrites. 



Structure schistose. Marked in part by veins of secondary quartz 

 in mosaic. The felspar is entirely clouded with decomposition pro- 

 ducts ; it lies irregularly mingled with very pale green fibrous horn- 

 blende. The latter has apparently developed at the expense of a pale 

 pink augite, of which a fair quantity remains ; in turn the hornblende 

 has here and there given place to chlorite. Irregular grains of a feebly 

 translucent mineral, probably leucoxene, are plentiful, and have a dis- 

 tinct tendency to linear arrangement. 



