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RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 207 
of the war, neither did I see Dalecarlia, but Dr. Twenhofel made some 
collections for me from the district about Rittvik, on Lake Siljan. 
In Norway, I visited, under the guidance of Dr. Holtedahl, the 
Ordovician sections in the vicinity of Christiania and, partly with Dr. 
Holtedahl and partly with Professor Kiaer, some of the exposures of 
Stage 4 in the Ringrike district. 
The description of the Palaeozoic strata of Sweden has been very 
ably summarized in English by Professor Moberg in his Historical- 
Stratigraphical Review of the Silurian of Sweden and a briefer sum- 
mary of certain facts in regard to the lower beds of the Ordovician 
has been published by Fearnsides (59). I am indebted to these two 
papers, and to the original sources from which their facts were derived, 
for the greater part of what is here set forth in regard to the geology 
of Sweden. The greater part of the Ordovician of Norway is still 
inadequately known. The account here is derived chiefly from the 
works of Brégger (93-95), and Holtedahl (97). No account in English 
of this section, except that in Geikie’s Geology, has, so far as I know, 
~ appeared. 
The strata of Ordovician age in Sweden are found in isolated patches, 
usually of small area. These patches may be grouped in bands, 
having a roughly parallel NE-SW alignment. 
The northern band, that in Jemtland and Lapland, has the greatest 
extent, running far north parallel to the mountains on the boundary 
between Norway and Sweden. These rocks are, however, except in 
the southern part, largely metamorphosed. The next band to the 
south of this has its best exposures in Dalecarlia, and there is a very 
small area in Gistrikland, especially on the little island of Lim6én near 
Gifle. From the evidence of boulders and fossiliferous sand in cracks 
on the Aland islands, it would appear that this band may once have 
connected with the Esthonian strata. To the westward the strata 
of the Christiania district of Norway are in line with these patches. 
The next band is in south-central Sweden, and includes the deposits 
in Nerike, Ostergétland, and Vistergétland, while the fourth band is 
at the extreme south and includes Scania and Oeland, while the Silu- 
rian of Gotland is in the-same line. The strata are best exposed and 
least disturbed in Vastergétland and Oeland. A brief description of 
the strata at some of the principal sections in each region follows. It 
is rather interesting to note that most of the principal lakes of Sweden 
are connected with these limestone patches. Thus we find Lake 
Storsjén in Jemtland, Siljan in Dalecarlia, Hjiilmaren in Nerike, and 
the largest lakes, Vinern and Vattern in connection with the Palaeo- 
zoic deposits of Viastergétland and Ostergétland. 
