MINERALOGTCAL NOTES. 
59 
potholes in the bed of the stream, which in its upper part is so 
small as not to contain running water in dry weather. It occurs 
also in fragments of a ferruginous conglomerate formed in the 
stream bed, and containing water worn rock fragments and crystals 
of zircon, thorite, &c. 
The mineral was traced to within a short distance of the head 
of the ravine, but no sign could be # found of any rock containing 
it in situ , and a more extensive search for the matrix would 
probably be a long and expensive matter, owing to the thick soil, 
landslips, and thick jungle. I have little doubt, however, that it 
is derived from some granitic or pegmatite-like rock, such as those 
in which zircon and allanite have been found. 
The mineral was detected in smaller quantities in washings 
from the Alupola-dola (some distance above the path) and in the 
Kuda-oya between Batataragala and the said Kondrugala path. 
Two or three crystals were also seen in gem washings from 
Massena estate, but more could not be obtained. A single crystal 
was found in a washing taken from the Pita-ela between Walawe 
and Morahela estates near Balangoda. 
Since uraninite is rarely found in cubic crystals, it is most 
probable that the mineral recorded by me as uraninite from 
Gampola [Spolia Zeylanica , vol. I. part IV., 1904), is in reality the 
new mineral. It there occurred in a pegmatite consisting mainly 
of orthoclase, quartz, and biotite, with apatite, tourmaline, &c., as 
accessory minerals. 
I have seen other specimens from Ceylon of a mineral resem¬ 
bling this one, but regarded as uraninite; some of these are massive, 
and cannot be definitely claimed as uraninite or thorianite without 
chemical analysis ; so that it is far from, unlikely that new 
localities will be found where one or both may be met wfith in 
greater abundance. 
IntheKuda Pandi-oya it is associated with quantities of zircon 
(well-developed large crystals, with some excellent twins on 
e (101)), and with more waterworn crystals of thorite, a mineral 
which I at first identified as monazite. A crystal of the supposed 
monazite stated to be from Bambarabotuwa was sent to the 
Imperial Institute for examination, and Mr. G. S. Blake’s analysis 
gave the following result, the mineral being identified as thorite :— 
Th 0, 
Ce 0 2 &c. 
66'26 Si 0. 2 
7*18 H 2 O 
14T0 
6*40 
2*23 
•46 
1*71 
0-35 
S. gr. 4-98 
99-89 
