^^^•57'] OF SOUTH-CENTRAL CEYLON. 207 



to mere lines. To these three constituents the microscope adds a 

 mineral, which I think is apatite. The magnetite is often embedded 

 in the garnet ; its outlines are irregular or sinuous. An angle or a 

 side of the garnet is often finished off by hornblende, and flakes of 

 the latter frequentlj^ connect small outlying grains of the former. 

 A few crystals of zircon are present. Quartz is abundant, and 

 occurs in the usual elongated grains, which occasionally divide and 

 ramify among the other constituents. The felspar is, for the most 

 part, orthoclase with microperthitic intergrowth ; but a little plagio- 

 clase is found. 



In some specimens the garnetiferous parts of the rock are repre- 

 sented by a short band, about '4 inch broad, composed almost 

 entirely of garnet, while in other places the mineral is aggregated 

 into patches. 



A specimen collected at the station before Bandarawella is essen- 

 tially the same as the banded rock of the quarry above described. 

 It is compact and greenish in colour, slightly banded, and with 

 a greasy lustre. The irregular outlines of the garnet and their 

 association with green hornblende, magnetite, and the apatite-like 

 mineral, merely repeat the characters of the Bandarawella rock. 

 A very few flakes of brown mica are found. The largest garnet is 

 about 0*10 inch in diameter. 



Similar rocks are met with by the new road which runs along the 

 side of the hill above Bandarawella village. The numerous cuttings 

 usually show the common sandy soil, which seems certainly to result 

 from the disintegration in situ of the gneiss. The bands which 

 characterized that rock are still clearly visible, and even the remains 

 of the garnets can be seen as reddish spots. A few small quarries 

 and road-cuttings show a little variation in the character of the rock. 

 Sometimes no garnets at all appear, and the rock is uniform when 

 seen from a distance. Frequently, however, closer inspection reveals 

 the presence of a few dark bands (specific gravity =3*16). Such an 

 one possessed green hornblende as its dominant constituent, while 

 a pleochroic augite was common, and biotite not rare. The rest of 

 the slide was composed of plagioclase, as usual quite translucent. 



A thin section cut from a banded rock near here showed that, as 

 in all instances met with of banded rock in Ceylon, no line of 

 demarcation could be drawn between the dark and light portions 

 of the slide. The darker parts contain hornblende and pleochroic 

 augite ; and, more sparingly, magnetite, brown mica, and garnet in 

 order of frequency. The greater part of the hornblende is an 

 alteration-product from the augite. The remainder of the specimen 

 is a light greenish rock containing large quartz-crystals, but as a 

 whole much finer in grain than those from the Station Quarry at 

 Bandarawella. Some red garnets about '03 inch in diameter catch 

 the eye, and also a few flakes of mica. 



(b) Eoad from Newara Eliya to Hakgala. — In the quarry 

 at the end of the lake at Newara Eliya occurs a dark greenish 



