Prof. Milne and Alex. Murray — Rocks of Neiifoundlctnd. 255 
lying as they clo at tlie very base of tlie Silurian. My last oppor- 
tunity of seeing these rocks was wbilst coasting along tbe shores of 
Bonavista Bay, especially in tbe neigkbourhood of Cutler’s Head, 
where they are exposed in cliffs several bundreds of feet in keigkt. 
The rocks are fine-grained, cbloritic, and argillaceous. In many 
places they are coloured witb red oxide of iron. Some of the rocks 
of tbis neigbbourbood of an amygdaloidal character appeared to be 
altered diorite. 
On tbe westem side of tbis headland there is a deserted monument 
of folly in the form of a small quarry, wbicb was vigorously worked 
upon under tbe impression tbat tbe compact argillaceous-like rock 
of the cliff was a mass of tin-stone. 
Furtber up tbe bay conglomerate and more igneous rocks of a 
chloritic character and lieb in kaolinized felspar were observed. 
Potsdam and Calciferous . 1 — Still ascending in tbe series, tbe next 
members are those of tbe Potsdam and Calciferous groups. These 
are to be seen in tbe nortbern and westem parts of tbe island. 
Tbe former of tbese groups consists of dark-coloured slates and 
conglomerates, containing recognized Potsdam fossils. The series 
amounts to upwards of 5400 feet in thickness. Penetrating tbese 
rocks I found dykes very similar to those I observed before, such as 
felsites and higbly chloritic melaphyres containing quartz. 
Tbe Calciferous series, whicb overlies tbe Potsdam, is one wbicb 
presents very different characters to any of the preceding. It is 
well exposed in tbe Western parts of the island upon the nortbern 
side of tbe Port au Port Peninsula, where it consists of definitely 
stratified grey limestones rieb in fossils, — large Orthosceri, Corals 
and Maclurea being very noticeable. These limestones weatber into 
tbick columnar forms, divided horizontally by joints, just as if so 
many buge discs witb rounded edges bad been piled one above tbe 
other. 
By tbe action of the sea and other causes, several cavems liave 
been excavated. Two of tbese I explored. One was wide and open, 
and about 70 feet in length; tbe 6econd, whicb was narrow and low, 
was about 130 feet in length. Some of tbese, on future exploration, 
may yield remains, beneatb tbe bed of clay witb wbicb their floor 
is covered, wbicb may be of interest in connexion witb tbe study 
of tbe modern fauna of tbe island. 
Quebec Group . — At the base of tbis group we get a vast series of 
graptolitic sbales, amounting to about 4000 feet in thickness. 
Above these sbales we bave a large display of serpentines and 
1 The passage upwards from the Paradoxides slates is very well displayed in Con- 
ception Bay, where there is no evidence of any want of stratigraphical conformity ; 
but it is difficult to teil in what part of the section the Primordial ceases, and the 
Potsdam proper begins ; a great mass of sandstone oecurs at Kelly’s Island, and 
there are alternating sandstones and black shales or slates, which form the largest 
island in the bay — Bell Island. The whole of these strata hold in greater or less 
abundance Cruziana similis, Billings, Eophylon Linnatanum , Torreil, several 
species of Livgula, and other forms which Mr. Billings was disposed to think were 
of Upper Potsdam type. These strata differ considerably from the beds Mr. Milne 
quotes, on the north and west sides of the Island, which are probably higher 
measures. — A.M. 
