190 
SPOLIA ZKYLANICA. 
stepped surfaces. These surfaces usually lie in the principal zones 
of the crystal, and meet in a central point (A, in figs. 2 and 3) to 
form a pyramid, which in most crystals has a quite flat base parallel 
to a (100) or m (110). The six-sided type shown in fig. 3 is very 
usual; such crystals do not at all suggest a zircon at first sight. 
At the centres (A) of the striated areas the crystals are pale in 
colour, transparent, and possessed of a brilliant adamantine lustre. 
Away from this point the colour gradually shades off into brown, 
and the transparency and lustre diminish. 
Further detailed examination showed that the crystals consist 
mainly of a dark brown zircon of specific gravity 4*0, which is 
optically uniaxial, usually intergrown with a lighter coloured 
variety of higher specific gravity which is optically biaxial ; the 
dark variety when heated changes to green in colour and becomes 
biaxial ; the pale variety when heated increases in density, but 
shows no optical changes. The two varieties are identical in 
crystalline form. 
It seems, therefore, that there are at least three classes of 
zircon :—- 
a Those of sp. gr. 4*0, which do not increase in density when 
ignited ; 
(3 Those of sp. gr. 4*7, also not increased in density when 
heated. 
y An unstable form of sp. gr. about 4*3, which when ignited 
is increased in density to 4*7. 
Zonal intergrowths of these varieties account for the properties 
of zircons with intermediate characters. 
A. K. COOMARASWAMY. 
2. Ornithological Records for 1904 .—The following notes on 
birds acquired during the past year under rare or peculiar circum¬ 
stances will be of interest in themselves and useful for future 
reference. In one case, that of the Short-eared Owl, the fact of its 
occurrence in Ceylon will be new to most ornithologists, although 
it has been known here since 1891. 
A.—Migratory Birds. 
The captures are recorded below in chronological order :— 
(1) A young male Sociable Lapwing (Chettusia gr eg arid) was 
shot near the Havelock Racecourse on 5th January and was 
purchased for the Museum, where it has been mounted and exhi¬ 
bited for the first time. The Museum previously possessed one 
