SKETCH OF 44GINA AND METHANA. 85 
is often accompanied by augite, occasionally to such an extent 
that it is difficult to decide whether a given specimen ought to 
be called a hypersthene-augite-andesite, or an augite-hypersthene- 
andesite. With one exception, however, it seemed better to 
group them all under the heading above, especially since the 
great majority of hypersthene-andesites elsewhere do carry more 
or less augite, while many augite-andesites are entirely free from 
orthorhombic pyroxene. The rocks richer in augite will be known 
as augite-hypersthene-andesite, while those which are quite free 
from, or very poor in, augite will be called hypersthene-andesite 
proper. The reason for making this distinction is the greater 
inasmuch as it corresponds quite exactly with the geographical 
distribution of the two varieties. The one exception mentioned — 
above is that of a rock entirely free from hypersthene, which is 
hence a true augite-andesite, and will be described in its proper 
place. 
In some of these rocks, notably in the products of the latest 
eruption at Kaimeni, hornblende is present in considerable quan- 
tity, and as the presence of this hornblende is correlated with 
structural and other characteristics, these specimens will be 
described later as hornblende-hypersthene-andesite. 
The list of localities at which hypersthene-bearing and 
hypersthene-andesites occur has been largely increased in the 
last few years, and their occurrence here is not at all surprising 
when it is recalled that they occur abundantly at Santorini and 
Milos and at Erimomilos which are on the same volcanic fracture 
line. This point will be referred to later. 
Hypersthene-andesite proper is found only on Methana. at 
the top of Mt. Chelona, at and above the acropolis of Methone, 
around the small harbor of Vathy on the west coast and at one 
point on the northeast coast. The augite-hypersthene-andesites 
make up the main mass of Mt. Oros and Mt. Kouragio on 
fZgina, while the augite-andesite proper is found at Agio Soma- 
tos near the Hellenic ruins. These sub-groups resemble each 
other so much and shade into each other so gradually that they 
may be described together. 
