CONTENTS. 



Page 



Introduction ^ 



Historical Review ^ 



Geology of the Localit\' at Tømten 6 



Material • ' ^ 



Pale o n tolo gi cal Section ^^ 



Liugtilella sp '^ 



Obolclla rotuiidata nov. sp ^^ 



Obolella iGlyptias) favosa Lnrs i6 



Acrothelf hellapmictata Walcott 17 



Scenella antiqita nov. sp '7 



Scenella depressa nov. sp i° 



Helcionella rngosa H.\ll '9 



Helcionella rugosa Hall. var. aaitkosta Walcott 20 



Torellella laevigata Lnrs. var. Holnii nov. var 20 



Hyolithiis corntgattis nov. sp 25 



Hyolithiis sp. No. i -5 



Hyolithiis sp. No. 2 26 



Hyolithiis sp. No. 3 26 



Volborthella tenuis Schm 27 



Weyntoiithia nobilis Ford 28 



Family Ellipsocephalidae -9 



Streiniella Matthew 3° 



Stretiiiella primaeva Brogger 3^ 



Streiniella Liiniarssoni nov. sp 3° 



Ellipsocephaltis Zenker • 4i 



Ellipsocephaliis Nordeiiskjøldi Lnrs 4' 



Development and Relationship of Ellipsocephalidae 4 4 



Familj' Mesoiiacidae •■ 54 



Hohiiia Matthew 54 



Holinia Kjeriilfi Lnrs 5° 



The ej'e "4 



Maculae of the h3'postome "5 



Articulation of the segments ^5 



Ontogenetical development "" 



Observations °9 



Holinia Grandis nov. sp 7° 



Kjerulfia nov. gen 7 i 



Kjeriilßa lata nov. gen. & sp 73 



Articulation of the segments 79 



Sj'stematic remarks "° 



Some general remarks on the structure and development of the Mesonaadae . . 8r 



L The obliterated Facial suture "' 



II. Hypostome and Hypostome attachments °i 



III. Development of the Mesonacidae "3 



StratigraphicalSection 94 



I. The stratigraphical occurrence of the fauna 94 



II. Our Lower Cambrian beds and their limits 99 



III. Paialielisation with certain other Lower Cambrian regions . . • 105 



