497 
of Edinburgh, Session- 1879-80. 
and Suderoe of clay, shale, and coal. The prevalent dip of the beds 
in the northern islands is south-easterly, but in Mygenses it is 
easterly, and in Suderoe, or the southern island, north-easterly. 
Nowhere does the strata incline towards the west. The angles of 
dip are generally very low — in the northern islands not averaging 
more than 2° or 3°, while in Suderoe they are a degree or so higher. 
The oldest part of the series is represented in Suderoe and 
Mygenses. The basalt rocks in these islands consist principally of 
bedded anamesites, composed of plagioclase, augite, magnetite, and 
olivine. Their behaviour in the field and the general aspect they 
assume are described in considerable detail. They are all more or 
less amygdaloidal. Very often the various sheets of old lava are 
separated by partings and layers of a red fine-grained palagonitic tuff. 
Near the top of the anamesite series occurs an irregular belt or band 
of shales and clay with two seams of coal. [The position of this 
belt was shown upon a coloured diagram, representing a section 
across the island of Suderoe.] A thin and local seam of coal and 
shale is found much lower down in the series. [This also was shown 
upon the diagram.] The distance between this local coal and the 
workable coal-beds above is about 1100 feet. The author next 
gives a detailed description of the various outcrops of the coal, and 
traces its extension over Suderoe. [The more characteristic appear- 
ances presented by the coal were shown in another diagram.] The 
two workable coal-seams vary in thickness from a few inches up to 
two or three feet respectively. They are mined to a small extent, 
and in a very primitive manner. 
The author next gives a particular account of the basalt rocks 
above the coal. It is these rocks which compose the major portion 
of the northern islands ; the only one of the north islands which 
shows any trace of the coals and the lower igneous series being 
Mygenaes. The basalt rocks above the coals are for the most part 
more coarsely crystalline than those of the older series. They are 
dolerites rather than anamesites, but their composition is the same. 
They are also as a rule more coarsely amygdaloidal — the cavities 
often reaching a great size— two feet and even more in diameter. 
The minerals they contain are chiefly chabasite, stilbite, apophyllite, 
analcime, quartz, calcedony, calcspar, and green-earth, and it is not 
uncommon to find two, three, or even four different zeolites in one 
