416 MR. A. K. COOMARASWAMY ON THE [ Aug. 1902, 
scattered through the limestone, for example, in the neighbourhood 
of Talatuoya, and also at Hakgala. The crystals are often well- 
shaped octahedra ; sometimes, as at Hakgala Limekiln, combinations 
of the forms (111) ard (101) are found. The largest crystals 
obtained im situ reached about 5 millimetres in diameter; but 
I have received much larger specimens, with the locality of which I 
am not acquainted, although they probably occurred in limestone. 
Blue spinel was noted as forming, with olivine and pale phlo- 
gopite, a small mineral-aggregate in limestone near Talatuoya. 
Pink spinel occurs in a micaceous mineral-ageregate in limestone 
in the middle disused quarry at Gettembe. Green spinels (green or 
black macroscopically, often nearly colourless in thin sections) are 
common in the dark patches and mineral-aggregates in the lime- 
stones, and associated with diopside or amphibole in contact-zones, 
and with green diopside, amphibole, and mica in the heavy green 
rocks which are sometimes found between the limestones and the 
typical granulites (Talatuoya, etc.).. Green spinels are rarely 
found scattered through the limestone, but seem to occur more 
definitely as a contact-mineral. Some varieties of limestone rich in 
green spinel are, however, to be met with, as at Talatuoya in the 
stream north of the bridge. 
The presence of spinel as a contact-mineral seems to result from 
the appropriation of silica in the formation of lime- and magnesia- 
silicates. 
(9) Apatite.—Blue apatite 1s everywhere common as an acces- 
sory mineral in the limestones, and associated with malacolite and 
phlogopite in mineral-aggregates in the limestone, as at Lower 
Albion, Hakgala. In the limestones it is present in the form of 
prismatic crystals, with rounded outlines, always big enough to 
attract attention. Isolated grains show (as was noted by Mr. Park- 
inson) a Clear pleochroism, namely, for rays vibrating parallel to ¢ 
sky-blue, for rays vibrating perpendicular to c’ pale claret (nearly 
colourless). In thin sections the blue apatite appears colourless. 
Dr. Schiffer has analysed a blue apatite from Wattegama, his 
results giving the calculated formula (PO,). (FICICa,. Prof. 
Church has also inv estigated the blue apatite of Ceylon." 
(6) Amphibole.—tThe amphiboles associated with the crystalline 
limestones are not especially abundant, but have been noted in 
several localities occurring as contact-minerals, silicate-aggregates, 
or scattered through the limestone. 
Fibrous crystals of colourless tremolite, with au extinction-angle 
on (110) of about 17°, form a white silicate-aggregate in limestone 
not far from the 36th milestone on the Kandy-Anuradhapura road. 
Colourless glassy amphibole occurs in nodular silicate-masses (with 
colourless mica and blue apatite) in limestone two-fifths of a mile 
south-south-west of Ulisna Mudunatrigonometrical station (P]. XIIT). 
A variety has a very faint greenish tinge, and some glassy crystals 
scattered through the limestone itself are of a clear pale-green. 
1 «Nature ’ vol. lsiii (1901) p. 464. 
