212 Capt. H. Lynes & W. Campbell Smith— 
differs in containing rounded crystals of olivine and a few crystals 
of labradarite ‘and pale-yellowish augite, which seem quite foreign 
to a rock of this nature. The labradorite is in one case enclosed in 
a crystal of anorthoclase; in another case the plagioclase is 
surrounded by a granular zone of untwinned felspar, augite, and 
magnetite. The phenocrysts of augite, wherever seen, are surrounded 
by a zone of small granular augites. Both the augite and the 
labradorite have the appearance of xenocrysts. This rock also 
contains numerous patches, 0°2mm. in breadth, with rectilinear 
boundaries and made up of blebs of an opaque mineral doubtiully 
referred to cossyrite ; these are probably pseudomorphs, but there 
is no evidence in the rock as to their origin. 
QUARTZ-BEARING RIEBECKITE-TRACHYTE. 
Two specimens (4 and 5) present a striking resemblance to the 
sdlvsbergites (Abuna Alif type) described by Prior! from the 
neighbourhood of Adowa and Axum, in Abyssinia, and which he 
compared to Brégger’s sélvsbergites from the Christiania district. 
The fresher specimen is cream-coloured, with minute black specks, 
giving the rock a blue-grey colour, stained red in patches. It 
resembles the Abuna Alif rock in texture, and in turbidity of the 
felspar laths, but differs in the possession of a few small phenocrysts 
(1'8 mm. < 0°8 mm.) of anothorclase, in the presence of quartz as 
interstitial patches sometimes0°1 mm. in diameter, and in the 
presence of abundant rebeckite in place of egirite. 
The mineral here referred to mebeckite shows two cleavages 
intersecting at about 120°, X:c = 5°, and pleochroism :— 
X = very deep blue-green. 
Y = very dark blue, almost black. 
Z = pale yellowish-green to olive-green. 
Some sections suggest egirite, but the green shades for X and Y 
are always very dark. A very similar rock (5) from the same locality 
is bright red in colour, which is due to the complete decomposition 
of the soda-iron-silicate, which may have .been either riebeckite 
or egirite. 
There is no evidence as to whether these rocks occur as dykes or 
flows. On account of the trachytic texture they are classed for the 
present as trachytes, but their close similarity to Prior’s sélvsbergites 
from Abyssinia must be borne in mind. 
ANDESINE-BEARING KENYTE. 
This specimen (6) is not strictly comparable with any of the rocks 
hitherto described from Kast Africa, but its relation to the kenytes 
is evidently a close one, and it is still more closely related to those 
rocks of South Victoria Land which Prior has referred to as inter- 
1G. T. Prior, Min. Mag., vol. xii, 1900, p. 267. 
