JOHAN KIÆR. M.-N. Kl. 



It therefore appears most natural to regard the typical Callavia zone 

 in the Atlantic province as belonging to the youngest part of the Lower 

 Cambrian series. 



This result is supported by the conditions in England. It is particu- 

 larly interesting to note the important investigations made in recent years 

 by E. S. CoBBOLD- in Shropshire^. We also find there that the Callavia 

 fauna are directly superimposed by a typical Protolemis fauna. It is not 

 until we arrive above the latter that we find a distinct break, conglomerous 

 beds being then succeeded by the Paradoxides Groouiii fauna with marked 

 discordancy. This interesting fauna shows some resemblance to the Par. 

 Ølandicus fauna in Scandinanavia [Cotwcoiyphe einarginata Lnrs.), but may 

 possibly be somewhat younger. 



As stated above, we consider it probale that our Hohnia fauna may 

 be parallelled with the Callavia fauna (in Shropshire and the Atlantic 

 Province in N. Ameria). The still older zones with fossils in Scandinavia 

 may also be regarded as contemporary with the above. 



They are all very closely allied as regards fauna, and important fossils 

 appear sometimes in one and at others in another. They must therefore 

 all be assumed to belong to the youngest part of the Lower Cambrian. 



As the leading forms of Mesonacidae are different in Scandinavia to 

 what they are in the English and N, American districts, the parallel must 

 be made by the aid of other elements in the faunae. We there find, it is 

 true, only a few directly agreeing forms. Discinella Holsti Moberg, hovewer, 

 probably agrees with the fossil that is regarded i N. America as opercula 

 to HyoUthellns niicans Bil. Furthermore, Helcionella rugosa Hall was found 

 in the Hohnia shales in Norway and in the Callavia zone in New Found- 

 land, and even exactly the same variety [acuiicosta Walc.) The rare 

 Microdisats uobilis Ford is also in remarkable accordance; it appears, 

 however, in N. America in a fauna of a more indeterminate character at 

 Troy in New York. 



Several closely related forms (vicarious) on the other hand can be 

 shown to belong to important genera such as Streniiella, Obolella, Scenella 

 and Helciojiella ; Volborthclla and Platysoleuitcs, too, are reported by Mat- 

 thew from the Atlantic province of N. America, 



The faunistic difference here found is assumed by the present writer 

 to be due to the circumstance that the Lower Cambrian ocean in Fenno- 

 skandia to a certain extent formed an independent faunistic province. Indeed 



1 On Trilobites from the Cambr. Rocks of Comley (Qu. Journ. G. S. Vol. 66, 1910). 

 Trilobites from the Parado.xides beds of Comley (Qu, Journ. G. S. Vol.67, 191 1). 

 The Tritobites fauna of the Comley breecia-bed (Qu, Journ. G. S. Vol.69, 1913). 



