486 Prof. C. Lapworth—Olenellus Fauna in Britain. 
of fair probability. With the Longmynd rocks would possibly go 
the Torridon Sandstone of N.W. Scotland, the Schists of St. Lo in. 
France, the Sparagmites of Norway, etc. Again, if the Wrekin 
Quartzite is, as has been more than once suggested, the extension of 
that of Nuneaton and Durness, then our so-called Upper Cambrian 
of the Malverns, Central England and N.W. Scotland, may be in 
reality a greatly attenuated representative of the Cambrian system 
in general, the British extension of the remarkably attenuated Pro- 
terozoic formations of Northern and Western Europe. If so, this 
attenuated Cambrian may eventually be mapped as patches of an 
originally, fairly continuous band, ranging from Lapland, through 
Esthonia, Scania, Norway, Scotland, Central England, France and 
Spain to the Island of Sardinia. The Sardinian and Durness for- 
mations on the extreme 8.E. and N.W. points of this line would 
agree in lithology, age, and fauna, both ranging from the base of the 
Cambrian up to the lowest zones of the Ordovician. It should care- 
fully be borne in mind, however, that in the present state of our 
knowledge these suggestions must be regarded simply as constituting 
a provisional working hypothesis, of service mainly as a stimulus to 
future discussion, investigation, discovery, and correction. 
Grouping together, however, such facts as are already known, and 
employing Mr. Walcott’s nomenclature, we are now able to parallel 
his American tables by the following European equivalents :— 
TasLe ].—North- Western Europe. 
Norway. SWEDEN. EstHontia. LAPLAND. 
. | Up. Cambrian Dictyonema Dictyonema Dictyonema Unknown. 
e or and Olenus. and 
& | Olenus zones, Olenus zones 
Pa 
SS ‘ Mid. Cambrian | Paradoxides Paradoxides Unknown ? 
ZB or Para- zones. 
e doxides zones. 
5 : 
s Low. Cambrian | Olenellus zones} Olenellus Olenellus Olenellus 
or 
{ Olenellus zones. 
Taste I].—British Islands. 
Suropsuire. |St. Davips Mentonrru- | Cznrrar | Dur- 
i i i SHIRE. ENGLAND. | NESS. 
; Up. Cambrian | Dictyonema Olenus, Dictyonema Dictyo- ' 
5 or and and nema and | 3 
i Olenus zones. Olenus zones. Olenus Olenus. | Sg 
na Si 
: i f : <8 
™ 4 Mid. Cambrian, Unknown Paradoxides} Paradoxides | Unknown | 4 & 
» or Para- a4 
a doxides zones ea 
: ae 
let . H 
3 Low. Cambrian| Olenellus Unknown Unknown Unknown 2 i 
oO | or a 
{ Olenellus zones 
