Parr IT, Sror.i.§2] | CAMBRIAN. 657 
sandstones of western Ross and Sutherland could not be paralleled with 
those of the eastern tracts of those counties, but must be of older date 
than part of the Llandeilo rocks of the Lower Silurian period. Sir R. 
- Murchison classed them as Cambrian—an identification which finds 
_ support in the lithological resemblance between these rocks of the north- 
west Highlands and much of the Lower Cambrian system of Wales. 
In-the south-east of Ireland masses of purplish, red, and green shales, 
_ slates, grits, quartz-rocks, and schists occupy a considerable area and 
attain a depth of 14,000 feet without revealing their base, while their 
top is covered by unconformable formations (Lower Silurian and Lower 
-Carboniferous). They have yielded Oldhamia, also numerous burrows 
and trails of annelides (Histioderma Hibernicum, Arenicolites didymus, 
A. sparsus, Haughtonia pecila). No Upper Cambrian forms have been 
met with in these Irish rocks, which are therefore placed with the Lower 
Cambrian, the unconformability at their top being regarded as equivalent 
to the interval required for the deposition of the intervening formations 
up to the time of the Llandeilo rocks, as in the north-west of Scotland. 
Some portions of the Irish Cambrian series have been intensely 
metamorphosed. Thus on the Howth coast they appear as schists and 
quartz-rocks ; in Wexford they pass into gneiss and granite. In West 
Galway a vast mass of schists, quartz-rocks, and limestones (8000 feet and 
upwards) passes up into schistose and hornblendic, as well as unaltered 
rocks containing Llandeilo fossils. These have been supposed by Mr. 
Kinahan to be probably Cambrian. He suggests that they are Upper 
Cambrian, which would imply that Upper Cambrian rocks pass conform- 
ably into ‘the Llandeilo formation without the occurrence of the thick 
Arenig rocks of Wales. In a difficult country, however, broken by faults 
and greatly metamorphosed, an unconformability might easily escape 
detection. According to Mr. Hull, the Galway and Mayo rocks contain 
no representatives of the Cambrian system. In his view the oldest 
portions (hornblende-schist, gneiss, &c.) are Archean, covered (uncon- 
formably, no doubt) by generally metamorphosed Lower Silurian rocks, 
above which come Upper Silurian non-metamorphosed strata. 
Continental Europe.—According to the classification adopted by 
M. Barrande, the fauna of the older Paleozoic rocks of Europe suggests 
an early division of the area of this continent into two regions or 
provinces,—a northern province, embracing the British Islands, and 
extending through North Germany into Scandinavia, on the one hand, 
and into Russia on the other, and a central-Kuropean Bene: including 
Bohemia, France, Spain, Portugal, and Sardinia. 
Passing from the British type of the Cambrian deposits we encounter 
nowhere in the northern part of the continent so vast a depth of 
stratified deposits. In central and northern Norway the Archean 
gneiss is overlaid by reddish and grey sandstones and conglomerates 
(Sparagmite), with schists, quartzites, and limestones. Above these rocks, 
which, according to Kjerulf, are partly coeval with the Archean series, 
lies the “ Primordial Zone” (p. 659). Near Kongsberg it is made up of 
a lower band (8 feet) of conglomerate, sandstone, and schist, followed by 
60 feet of black shales with Paradowides Tessini, P. rugulosus, Agnostus 
_ fallax, A. parvifrons, A. gibbus, A. incertus, above which come more dark 
shales (22 feet) with Paradoxides Forchhammeri, Agnostus Kjerulfi, A, 
brevifrons, A. aculeatus, Protospongia, &c. In the Christiania district 
_ there occur (1) a lower zone 9) Norwegian feet thick, composed of con- 
ZOU 
