Yol. 56.] CEYLON KOCKS AND GKAPHITE. 597 



* quartz de corrosion ' than is the case with the sharply -defined 

 vermicular quartz often occurring in the felspars, where its presence 

 is probably due to the contemporaneous intergrowth of the two 

 minerals. 



Galle. — A light-grey rock with scales of graphite, associated 

 with the wollastonite-scapolite- bearing rocks, consists of microcline 

 and some orthoclase-microperthite and quartz (elongated), and also 

 very little sphene, augite, apatite, secondary calcite, and muscovite. 



A vein, apparently intrusive in the same series, is very similar, 

 but contains a little plagioclase and hornblende and has no graphite. 



South of Galle Harbour a new path has been made from the 

 shore to the plague-camp established on Buena Vista Hill, and near 

 the top fresh specimens are obtainable from the blasted rock. 

 The rock is greenish-grey, and shows a greasy lustre. The rather 

 large felspars resemble those seen in laurvigite, but have no blue 

 sheen. The minerals are orthoclase-microperthite and quartz, with 

 also plagioclase and a very little pyroxene, ilmenite, zircon, and 

 apatite. The structure is not granulitic. 



Ambalangoda. — Immediately north of the little river is a small ' 

 rock -exposure projecting from the sand, containing what was 

 apparently a dark vein about 8 inches wide. A section of the 

 4 junction of rock and vein ' shows that the former is a quartz- 

 felspar (chiefly plagioclase) rock with very scarce biotite, magnetite, 

 apatite, and rhombic pyroxene. The quartz-grains are elongated. 

 This granulitic rock appears uncrushed up to the ' junction/ where 

 however, there is every appearance of shearing. The very minute 

 biotites are arranged in a stringy way, so as to include lenticular 

 areas of quartz and felspar. As one proceeds farther into the ' vein ' 

 the shearing becomes less evident, though for nearly J inch included 

 in the slide it has a crushed appearance, which the outer rock has 

 not. The more abundant biotite chiefly distinguishes the dark 

 4 vein ' from the outer rock. It seems clear that an old line of 

 shearing has been recemented. It is noteworthy that this is the 

 only Ceylon rock that I collected wherein clear evidence of 

 mechanical deformation appeared. 



Ragedara. — Normal garnetiferous granulites were noticed at 

 the graphite-mines, where they were also found by Dr. Diersche. 



Kalawewa. — Following the bund past the P.W.D. bungalow, 

 about 1| miles from it the road ultimately leaves the great reservoir. 

 A greyish-green rock collected at this point resembles that from 

 Buena Yista, Galle, consisting essentially of orthoclase-microperthite 

 (PI. XXXIII, fig. 5) and quartz, with some hornblende and very 

 little plagioclase, augite (?), magnetite, and zircon. In this and the 

 Buena- Yista rock the microperthitic structure is very clearly seen. 



Anuradhapura. — A normal granulite without garnet occurs 

 near the Newerawewa sluice, where the outflow runs under the 

 road. A specimen collected on the Anuradhapura road, nearly 

 69 miles from Kandy, is a yellow rock with minute garnets : it is 

 a normal granulite. 



