38 LTE, JO ORNATE OT MNGTROWOG VA 
In the Mt. Kouragio rocks, however, it is more coarsely granular. 
and apparently little coherent, as the original crystal outlines 
are quite lost and the granular masses rounded and washed away 
by the moving magma. 
The plagioclase phenocrysts are of good size and show many 
more planes than the smaller groundmass crystals. They seldom 
show twinning lamellz and the one case where measurement was 
possible gave an extinction angle of 25°. They bear as inclusions 
small hypersthene and apatite needles and spots of glass. Some 
of them show a peculiar core composed of a micropegmatite of 
what may be either two different feldspars, or particles of the 
same feldspar, but oriented in two different directions. 
In the rock which forms the small hill of the Methone acrop- 
olis there are present quite numerous phenocrysts of olivine 
which can also be seen with the naked eye. These are rather 
irregular in shape and often broken, though showing traces of 
crystal faces. They are colorless and quite fresh except on the 
edges, where they are generally colored bright yellow through 
incipient decomposition. Such an olivine-bearing hypersthene- 
andesite also occurs in one specimen from near Vathy Harbor, 
and from the west slope of Mt. Oros. The last specimen differs 
from the other rocks of the district in being of a pale brown 
color, very compact, with subresinous luster and with numerous 
phenocrysts. 
Flornblende-Flypersthene-Andesite—This has a special interest 
as it forms the material poured out by the eruption of ca. 250 
B. C., and hence represents the latest eruptive product of the 
region. It is also represented by specimens from a loose block 
on Mt. Chelona and from near Agios Georgios on the northeast 
coast. The Kaimeni rocks are, however, of the most impor- 
tance and the following description applies chiefly to them. 
They are not very compact rocks, containing numerous pores 
and in some of the specimens assuming a quite scoriaceous char- 
acter. They are highly porphyritic, showing, when fresh, a light 
gray, fine-grained, but dull and not very compact groundmass, 
with many phenocrysts of plagioclase and black hornblende, 
