Introduction. 



Tomten in Ringsaker is one of the most interesting localities in 

 Norway with respect to paleontolog}- and stratigraphy. It was there that 

 the first certain Lower Cambrian trilobite fauna were discovered in 1870 

 by the well-known Swedish paleontologist, J. G. O. Lix.narsson. 



It is true that Swedish scientists such as Torell, Linnarssox, and 

 Nathorst before the above date had shown the existence in Sweden of 

 a little fauna that mainly consisted of Brachiopods in the oldest coarse 

 clastic sedimentär}- series, which Angelix distinguished b}- the name Regio 

 fitcoidarum; but the discover}- of a new form resembling para.ioxidcs in 

 strata corresponding to the oldest series was something new, and in con- 

 sequence attracted considerable attention. 



The form was designated by Lixxarssox as Paradoxides Kjenilfi. 

 At first it was not observed that this fauna differed from the Middle 

 Cambrian. Axgelix's classification of the lower series was also made on 

 the basis of differences of sedimentary development. 



W. C. Brøgger was the first to demonstrate the divergence of the 

 new form from Paradoxides, and its affinity to the American Oletièllus 

 forms, a view with which Lixxarssox subsequently concurred. 



It was thus possible for Scandiavian paleontologists, — particularly 

 W. C. Brøgger in his work "Om alderen av Olenelluszonen i Nord- 

 Amerika", 1886, — to prove that American geologists had made a mistake 

 in regarding the Oletiellns fauna as younger than the Paradoxides fauna. 



For this reason in particular, the Lower Cambrian fauna at Tømten 

 has frequently been described and discussed in literature. Certain form? 

 of this fauna, as for instance the abundant and typical trilobite Olenellus 

 iHohnia) Kjenilfi Lxrs., have formed the subject of several descriptions, 

 amongst which we may specially mention an excellent one by Holm in 

 1887; but the fauna as a whole has not been exhaustively treated. 



Vid.-Seisk. Skrifter. I. M.-N. Kl. 1916 No. 10. 1 



