Linnarsson — On the Eophyton Sandstone. 393 



crag been exposed to the weather for a long period after the amelio- 

 rated climate set in we should not have had this interesting record 

 of ice-action, but an undecipherable heap of rock-fragments. 



The exceeding abundance of Diatomaceous remains is remarkable. 

 In this respect the deposit is such as might, with some slight modi- 

 fication of external causes, be the equivalent of the famed Lough 

 Mourne and Lough Island ; Eeavy strata in Ireland ; the Eaasay, 

 Peterhead, and Mull beds in Scotland ; and the Dolgelly earth in 

 Wales. That they have not been detected in the English clays 

 probably arises more from lack of examination than from any dearth 

 of these organisms. 



Note. — Mr. J. Wallace Young, of this city, has directed my atten- 

 tion to the presence of titanic acid in the laminated clay, as well as 

 in some of the adjacent rocks. The proportions varied from -94: per 

 cent, in the clay to 2.93 per cent, in one specimen of felstone. In 

 an examination I have just made of the upper leaf-bed I find it to 

 contain -80 per cent, of titanic acid. 



IV. — On some Fossils found in the Eophyton Sandstone, 



AT LUGNAS, IN SwEDEN.^ 



By J. G. 0. Linnarsson. 

 [Plates XI., XII., and XIII.] 



NO other part of Sweden affords more favourable opportunities for 

 studying the earliest fossiliferous deposits and their relations to 

 each other than Vestrogothia, with its unusually complete, undis- 

 turbed, and, in many natural sections, exposed series of strata. Its 

 two lowest principal layers, consisting of sandstone and alum-slate, 

 are to be referred to the Cambrian system, if that system, as pro- 

 posed by Sir Charles Lyell, Salter, and others, be extended over the 

 " Primordial zone," which is easily distinguished by its organic re- 

 mains from the overlying Silurian deposits. This sandstone has 

 long been known as the oldest stratum of Vestrogothia above the 

 Fundamental Gneiss. Traces of seaweeds were found in it by our 

 earlier geologists, and caused it to receive the name, still commonly 

 used, of Fucoid sandstone. Deposits of the same period are dis- 

 tributed over large parts of Scandinavia ; and Professor Angelin, 

 who, like his predecessors, had found them to be the oldest portion 

 of the whole " Transition formation" of Scandinavia, included them 

 all in his regio Fucoidarum, no other Fossil having as yet been found 

 in them. Norwegian authors have proposed the denomination 

 " Sparagmite stage," for the rock prevailing in Norway, which has 

 not as yet afforded any fossils, a term also adopted by Professor 

 Torell. 



Until lately few additions had been made to our knowledge of the 

 organic remains preserved in the deposits of the regio Fucoidarum. 



^ Translated from the Ofversigt af Kongl. Vetenskaps Akademiens Forhandlingar, 

 March 10, 1869. 



