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mus sp. and Agnostus pisiformis Linn., which proves them to come 
from a region of Cambrian deposits, which was exposed to erosion 
during the early part of the Lower-Silurian period. ANDERSSON (l.c. 
p. 79) himself is wrong in inferring from these erratics, that they 
come from the very locality whence originated also the boulders 
they contained, and that at the very least in that place the whole 
Upper-Cambrian must have been eroded away. I think this need 
not be so at all, and I even believe that it is most likely not the 
case, but that the region, from which these Cambrian blocks origi- 
nate, has to be looked for rather in the vicinity of the original 
locality of the Silurian erratics. First of all we think of the districts 
near the coast of the mainland of Sweden to the West and to the 
North of Gotland. 
The cementing material also which consolidates the phosphorite 
blocks, varies more or less from the first-mentioned erratics, as, 
according to J. G. ANDERSSON it sometimes consists of grey to white 
spotted coarse-crystalline limestone and sometimes of grey, compact 
limestone, in which occur a larger or smaller number of rounded 
quartz-grains, as well as occasionally some glauconite. 
Among the fossils in the last-mentioned erratics are Orthisina 
sp., Platystrophia biforata Schloth., Strepula sp. Tetradella sp., 
Asaphus sp., Illaenus nuculus Pomp., Lllaenus sp., some Bryozoa 
and other non-deseript fossils. Of all these only /d/laenus nuculus 
Pomp. was known hitherto from a boulder from East-Prussia, 
as described by Pomprcks (16 p. 69). The author referred it to the 
Lower-Silurian period. This rock consists of brownish, coarse-grained 
limestone with many quartz-granules. 
Finally we refer to one more erratic block with Strophomena 
Jenteschi Gag. from the North-Baltieum, recorded by Wiwan (23 p. 
103), viz. N° 94 of Ekeby. This boulder consists of red Asaphus-lime- 
stone and does not contain other fossils. 
The age of all these erratic blocks could be established, because 
Strophomena Jentzschi Gag. has been found in solid rock first by 
ANDERSSON (l.c. p. 77) in the northern part of Oeland, afterwards 
by Lamansky (22 p. 177) on the Wolchow in Russia and finally by 
Hourepaur (29 p. 46) in South Norway near Vaekkerö and Töien. 
Lamansky (le. p. 177) suspects that also the brachiopod, which 
is recorded by Broécerr (5 p. 50 pl. XI, fig. Va) as a Strophomena 
rhomboidalis Wilek. from the Expansus-shale and the lower part 
of the Orthoceras-limestone of South-Norway, is identical to 
Strophomena Jentzschi Gag. The figure alluded to, is not at all like 
it, as already observed by HoLTEDAHL. 
