466 Proceedings of Royal Society of Edinburgh. [sess. 
end — and which has been called Graptolite Island. Here three 
fossils were got. One of these is a graptolite, which has been 
examined by Miss Elies, who considers it to be part of a Pleuro- 
graptus. This would make the bed correspond in age with the 
Hartfell shales — almost the uppermost beds of the Ordovician 
system. The others have been kindly examined for me by Dr 
Peach. As is seen in his Note, he considers them to be parts of a 
Phyllocarid crustacean, probably nearly allied to Discinocaris, a 
form typical in this country of the Lower Birkhill shales, at the 
base of the Upper Silurian. 
If this is the case, then there is here an association in one bed of 
two forms which, in the South of Scotland, are characteristic of 
two different but at the same time closely contiguous zones. 
As regards the structure of the island as a whole, it is un- 
fortunate that the data regarding the dip and strike of the rocks 
are rather meagre. This is due partly to the fact that so much of 
the area is covered by ice, and partly because in so many places 
the dip could not be made out. The most common strike of the 
rocks is north-westerly, varying from N.N.W. to W.N.W., 
the dip being in most cases at a high angle north-easterly or 
south-westerly. One definite anticlinal axis was observed, running 
in a N.N.W. and S.S.E. direction. In a few localities other 
directions of strike were noted, but these were nowhere of large 
extent, and are probably only local contortions. 
Laurie Island itself, although its greatest length is in an E.N.E. 
and W.S.W. direction, consists of a series of peninsulas and hill 
ridges, running in a general N.W. and S.E. direction, with deep 
bays between adjacent peninsulas, and usually low cols crossing the 
island from the head of a bay on the north side to the head of 
another on the south side. 
The same structure is repeated in the group as a whole, which, 
though it extends furthest in an east and west direction, is cut up 
by two large straits, which cross it in about a N.N.W. and S.S.E. 
direction. 
These two sets of facts — the strike of the rocks and the general 
alignment of the hill ridges — lead one to believe we have here to 
deal with a series of plications whose axes run in a general N. W. 
and S.E. direction — probably rather nearer N.N.W. and S.S.E. 
