240 Correspondence—J. B. Scrivenor. 
small that it is impossible to base any conclusions on the examination, 
but the following notes may be of interest to anyone who has time 
and opportunity to examine larger specimens. 
The most interesting point observed in my specimen is the abundance 
of rutile, in the form of ‘‘ sagenite webs’’, in the mica. A separation 
of powdered rock in a liquid of 2°8 sp.g. afforded a lot of them. 
They are visible in the slides too, but their abundance is only 
appreciated in preparations where the mica flakes are lying flat. In 
addition to rutile I obtained a few grains of brookite and one crystal 
that resembles anatase. One little plate of brookite, with clear 
erystal outline, gave a good axial figure. This unfortunately was 
either lost or turned on edge when mounting the heavy minerals in 
balsam, but two other minute grains give figures with a 14 in. oil 
immersion objective. 
With regard to the origin of the small-flaked mica I am inclined to 
think it is certainly derived from the felspar, of which I was able to 
separate enough for two microscope preparations, and there is evidence 
too of some of the large-flaked mica being derived from felspar. With 
regard to that containing the sagenite webs, the latter are unusual in 
muscovite, in fact I do not remember ever seeing them, and their 
presence suggests that the mica may originally have been a dark mica 
which has become bleached, but not completely so. On the other 
hand, it might be argued against this that the mica containing the 
webs has an axial angle about equivalent to that of muscovite, but 
the idea that the rock originally contained a dark mica is strengthened 
by the fact that some of the quartz-grains enclose minute flakes of 
biotite. 
Apatite and zircon occur, and I found a few minute grains of 
a mineral like cassiterite. One showed a carmine pleochroism 
common in cassiterite, although not mentioned in textbooks. I was 
unable to prove anything, however, about these grains. Some may 
be sphene. 
I found two grains of tourmaline, and tested the mica for lithia with 
negative result. 
J. B. Scrrvewor. 
GEOLOGIST’S OFFICE, BATU GAJAH. 
March 2, 1916. 
MISCHIUMANHOUS. 
Tue Zootocicat Recorp For 1914. 
This work has made its appearance a little later than usual owing 
to the difficulty in getting some of the literature. The volume for 
1915 is well in hand, and it is hoped will be ready by next Christmas. 
At present it is the only work of reference from which one can gather 
the paleontological results of the year. The part containing any 
special group of animals can be had separately from the publishers, 
the Zoological Society of London. 
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