W. G. Fearnsides—Lower Ordovician Rocks of Scandinavia. 257 
Specimen II. Although the state of the specimen is not such as to 
justify the use of a name, it is possible that it represents a fragment of 
Weichselia, and if so, the age may be put down as Wealden. This 
comparison is made with considerable hesitation, and it is not one to 
which any weight should be attached. 
Specimen ILI. Cladophiebis so. It is convenient to adopt this 
generic name as a designation for the pieces of pinne bearing 
pinnules of the Cladophlebis type. 
The resemblance to Alukia exilis, while suggestive of a Jurassic 
horizon, is of practically no value, as this form of pinna is one of the 
commonest among ferns of different ages. 
IIJ.—Tse Lower Orpovicran Rocks or ScanpDINAVIA, WITH A 
Comparison oF BrrrisH AND ScaANDINAVIAN TREMADOC AND ARENIG 
Rocks. 
By Wittram G. Frarnsrprs, M.A., F.G.S., 
Fellow of Sidney Sussex College, Gaibrdes’ 
(Wir A coLouRED Foxiprne-Sxcrion, PLATE VIII; ann PLATE IX.) 
Introduction. 
S a worker among the Lower Paleozoic rocks of Wales I have 
for some years devoted a good deal of time to the study of 
Tremadoe and Arenig rocks, and in common with others have therefore 
often wished to check the results attained in that district of great 
thicknesses and tectonic complication by reference to the thinner and 
more fossiliferous series of the undisturbed areas of Northern Europe. 
When, therefore, the Senate of the University of Cambridge granted 
me the Worts Fund for travelling scholars, and instructed me to 
study the interrelationships of the Tremadoe and Arenig Series in 
Scandinavia, I at once took advantage of the opportunity, and spent 
the months of May, June, and July in hammering over those rocks in 
the field. a 
The course of my journey took me through Skane, Oland, Dalarne, 
the Gefle and Upsala district, Ostergdtland, Vestergétland, and the 
Kristiania and Eker districts of Norway in order, and with the 
exception of Nerike I was able to visit almost all sections where 
the Lower Arenig has been seen to rest upon Tremadoc rocks. The 
sections visited have all been described or mentioned in various local 
memoirs by Swedish or Norwegian geologists, but I have not been 
able to find any detailed English account of them, and as also I have 
not met with any comparative account of the variation of the various 
members of the succession in the different districts, I have thought 
that a systematic stratigraphical account of the rocks as taken from 
my own field observations may be of interest. 
The present communication, therefore. though based entirely upon 
my own field notes, makes no pretence of recording new facts, and is 
only original in so far as it is comparative, and that its comparisons 
seem to bring out certain new evidence as to the physical conditions 
during ‘l'remadoe and Arenig time. Except in the matter of the time 
variations shown by Dictyonema which is here put forward and 
DECADE Y.—VOL. IV.—wNO. YI. 7 
