146 Prof. G. Linnarsson — The Oldest Rocks of N. Europe. 



parallelized witli the Paradoxicles Schists of Scandinavia. The Trilo- 

 bites of the Harlech group belong, most if not all, to the same 

 genera as those characterizing the Menevian group, for Plutonia is 

 hardly anything but a Paradoxicles with granulated shell (such as, 

 for instance, Paradoxicles ForcJihammeri, which occurs in the higher 

 divisions of the Swedish Paradoxides beds), and PaloBoijyge seems 

 still to be very doubtful. The specific differences do not seem to be 

 important enough to justify the separating of the Harlech Trilobite 

 fauna as a distinct fauna of the same rank as that of the Menevian 

 group. Then one could with the same reason in the Menevian group 

 distinguish a fourth and fifth fauna and so forth, there being several 

 divisions containing each their peculiar species. Even in the Para- 

 doxides beds of Scandinavia there are several subdivisions, the 

 fossils of which are, in general, specifically different, but one finds 

 so many generic links, that one must consider them altogether as 

 one single whole. Taken as a whole, the fauna of the Paradoxides 

 beds of Scandinavia is quite analogous to that of the Menevian 

 and Upper Harlech. Among the Trilobites there occur in the Para- 

 doxides beds, besides many other genera, Paradoxides {AnopoJemis, 

 Plutonia), ConocorypJie {Erinnys), Microdiscus, Arionellus and Agnostus. 

 Of other classes one finds Lejjerditia, Hyolithus, Lingulella, Obolella, 

 Ortliis, Protospongia, etc. If one may judge from the generic identities, 

 the Paradoxides beds of Scandinavia are therefore to be parallelized 

 to the above- cited British beds. I will not, however, positively deny 

 that part of the Harlech beds with Trilobites are possibly older than 

 the lowest Paradoxides beds of Sweden. Even if that be admitted, 

 the difference of age cannot be considerable, as the general character 

 of the faunas is quite the same, which would hardly be the case if 

 any long period had elapsed between their formation. 



Below the Paradoxides beds in most Cambrian districts of Scan- 

 dinavia a sudden change takes place in palseontological as well as 

 lithological characters, though the beds are always, as far as hitherto 

 known, quite conformable. The underlying beds are almost ex- 

 clusively sandstones. Only in Norway, and perhaps in the north of 

 Sweden, they contain any considerable intercalated beds of schists 

 and limestone. In a palgeontological respect the most striking 

 character of these sandstones is the total absence of Trilobites. 

 More difficult is it to affix to them any definite positive characters, 

 as the true nature of many of their fossils is still very uncertain. 

 The Fucoid Sandstone has yielded only two species of Lingididce, 

 besides tracks and burrows of worms or other animals and casts of 

 seaweeds. Far richer is the fauna of the underlying Eophyton 

 Sandstone. It consists of Brachiopods, Pteropods and Spongi^, 

 besides forms of more uncertain affinities, such as Cruziana, Harlania 

 (Arthrophycus) Eophyton, and many others. These latter forms are 

 only casts and tracks, and give but little information of the organisms 

 which produced them. For the identification of the strata they 

 cannot be used, as very similar casts are found in rocks of almost 

 every age. Thus I have seen a Harlania from the Ehsetic beds of 

 Scania, hardly distinguishable from a species occurring in the 



