Linnarsson — On the Eophyton Sandstone. 395 



formation, there is, at least, great probability that these deposits be- 

 long to the same period, and that the whole regio Fucoidarum is to 

 be regarded as a representative of the lower part of the Cambrian 

 system. If that be not admitted, it must be supposed that the regio 

 Fucoidarum has no equivalent in England, and that Sweden is deficient 

 of every deposit from the earlier Cambrian period. For such a sup- 

 position, however, no sufficient reason can be afforded. The occur- 

 rence of plant-remains cannot be regarded as such, at least so long 

 as nothing corresponding has been known from the Ui^per Cambrian, 

 and Brachiopods have now been found also in the Longmynd forma- 

 tion. As even the Longmynd formation is said to contain one or 

 perhaps more Brachiopods common to the Lingula-flags,' the break 

 between these formations cannot be very considerable, and we have 

 thus additional reason to give to the Cambrian period a longer dura- 

 tion than Sir E. Murchison has assumed. This circumstance and the 

 great dissimilarity between the faunas of the Upper and Lower Lin- 

 gula-flags has induced some English writers to refer to the Lower 

 Cambrian system not only the Longmynd group, but also the Lower 

 Lingula-flags.^ Accordingly the regio Gonocorypliarum should also be 

 referred to the Lower Cambrian system. The great geognostical 

 resemblance, however, between the regio Gonocorypliarum and the 

 regio Olenorum makes it more suitable, if a tripartition of the system 

 (into a lower, a middle, and an upper stage) be not preferred, to 

 refer them both to the upper division, at least till some closer palgeon- 

 tological relation, than any hitherto shown, shall have been dis- 

 covered between the former and the regio Fucoidarum, or between 

 the Lower Lingula-flags and the Longmynd formation. While thus 

 referring, with Sir Charles Lyell, both portions of the " Primordial 

 zone," characterized by Professor Angelin, to the Upper Cambrian 

 system, I still think that the " Tremadoc group " is to be excluded 

 from that System, and, together with its nearest equivalent in Sweden, 

 the regio Ceratopygarum of Professor Angelin, to be regarded as the 

 lowest portion of the Lower Silurian. 



The sandstone layer of Vestrogothia belongs as a whole to the 

 regio Fucoidarum, but in some other parts of Scandinavia there are 

 deposits of Sandstone also belonging to the younger Cambrian period. 

 Thus in Norway the "Hoejfjelds Kvarts" forms a part of the pri- 

 mordial zone, the stage 2 of Professor Kjerulf.^ In Oeland, at the 

 base of the alum-slate layer, lies a "calcareous quartz-schist"* in 

 which the earliest genera of Trilobites have been found, and which 

 by reason of its fossils has been referred by Professor Angelin to his 

 regio Olenorum^ but which, with greater show of reason, might be 

 referred to the regio Gonocorypliarum. In Vestrogothia the same 

 forms occur in the lowest part of the alum-slate, to which the quartz 

 schist of Oeland is thus equivalent. 



1 L. c, p. 2. 



2 See Th. Belt, Oa the "Lingula-flags," or "Festiniog Group" of the Dolgelly 

 District. Geol. Mag. 1867, p. 493 et seq. 



' Kjerulf, Stenriget og Fjeldlajren, p. 212. 



* A. Sjogren, Anteckningar oni Oeland. Ofversigt af K. Vet. Akad. Forhandl. 1851. 



