I916. No. 10. THE LOWER CAMBRIAN HOLMIA FALTNA. 97 



long known form the underlying bed of this shale, there was commonlv 

 found in the shale the remarkable Volborthella tenuis Schm.. which although 

 very rarely also appears in the Hohuia zone. About 5 meters up in the 

 shale were found 4 banks of calcareous quartzsandstone, separated from each 

 other by thin layers of green shales rich in mica. In the uppermost of 

 these there was discovered by Brastad numerous remains of the tinv, 

 interesting Brachiopod Discinclla Holsti Moberg. In the same bank a Medii- 

 sitia sp. was found by \'. M. Goldschmidt in 1910. 



The green shale series, the dimensions of which cannot with certaintv 

 be determined, 130 — 40 m.?) thus contain in this district 3 difterent fauni- 

 stic zones : 



1. The zone with Discinella Holsti Moberg in the lower part. 



2. The zone with Hohnia Kjcnilfi Lnrs. in the middle part. 



3. The zone with Stremiella Linnarssoni Ki.er in the upper part. 



We ma}- now pass over to an investigation of the relationship of this 

 zone to 3'ounger and older deposits. 



As we have stated, (page 9), only a portion of the Ho/niia shales are 

 exposed at Tomten; the transition to the Middle Cambrian is quite cove- 

 red. At Evjeviken, where we see the uppermost zone (that containing 

 Stremiella Linnorssoiii) we are likewise unable to study very closely the 

 faunistic transition. It is not until we reach farther south, at Krokviks- 

 bugten and Vindju elan det, that the beds are better exposed. The 

 profile there was described by Brogger ^ in 1882. 



The beds at that place are markedly folded and repeated bv faults. 

 It is therefore not possible to determine the extent of the zones, but undoubt- 

 edly within these fault-lines we have the various zones in their original 

 sequence. 



Far to the south, at Krokviksbugten, we find above the quartzsand- 

 stone, argillaceous shales in thin beds alternating with. quartz schists; one 

 large rounded ellipsoid of blue calcareous sandstone is seen, in which Ama- 

 nuensis Brastad in 1915 succeeded in finding Torellella laevigata. This 

 appears to be what is known as the sandstone shale with trails. 



Above this are the argillaceous shales with rust flakes, to some degree 

 like the Hobiiia shale. It was there that in 191 5 BrAstad discovered a 

 fragment of Hohma Kjenilfi. The sandy limestone beds in the zone with 

 Stremiella Limiarssoui cannot be seen; on the other hand we see that the 

 grey-green shale series towards the north first alternate with dark grey 



1 Parado.xides Ølandiais-mvket ved Ringsaker i Xorge (Geol. Foren, i Stockholm Förh, 

 F>d. VI, pag. 143). 



Vid.-Selsk. Skrifter. I. M.-X. Kl. 1916. No. 10. 7 



