390 C. D. Walcott — Position of the Olenellus Fauna. 



Resume of Fauna. 



Genera. Species. Varieties. 



Spongias 3 3 



Hydrozoa 2 2 



Corals 5 9 



Crinoidea 1 1 



Trails, burrows and tracks . . 4 6 



Brachiopoda 10 27 



Lamellibranchiata 2 2 



Gasteropoda 5 10 5 



Pteropoda 4 15 2 



Crustacea - 3 5 



Trilobita 16 46 2 



Total 55 127 9 



The Olenellus Fauna in Europe. 



Until the memoir of Holm's on Olenellus Kjerulfi* ap- 

 peared, American paleontologists were unwilling to admit that 

 the genus Olenellus was represented in Europe. The figures 

 and descriptions given by Linnarsson and Brdgger were unsat- 

 isfactory, and they did not care to change the scheme of classi- 

 fication proposed by Logan without very positive evidence. 

 Personally I avoided referring to the debated question while 

 engaged in its study in America and while waiting for fuller 

 data from Europe. I felt the force of Brogger's argument, 

 but preferred to wait for stronger proof before accepting or 

 rejecting the European view. 



To the American fauna I will add the European forms that 

 are at present known to me : 



Scandanavia. — Holm statesf that according to Linnarsson 

 and Brogger, the fauna of the Olenellus zone in Scandanavia 

 consists of : Olenellus Kjerulfi Linnars., Ellipsocephalus Nor- 

 denshioldi, Arionellus primaivus Brogger, Hyoliihes sp. 

 undet., Metoptoma sp., Lingulella f Naihorsti Linnars., Ooolus 

 sp., Discina f sp. 



From the Eophyton sandstone beneath the Olenellus Kjer- 

 ulfi zone Linnarsson described^ JBythrotrep>Ms sp., Medusites 

 radiata Linnars., Medusites Lindstromi Linnars., Mick- 

 witzia Monolifera Linnars., Hyolithes levigatus Linnars., 

 Arenieolities spiralis Torell, Frcena tenella Linnars., Cru- 

 ziana dispar Linnars., Scotolithus mirdbilis Linnars., Eophy- 



* Aftryck vr. Geol. Foren. Stockholm, Forhandl., vol. ix, haft 7, 1887. 

 f Aftryck vt. Geol. Foren. Stockholm, Forhandl., vol. ix, haft 7, p. 22, 1887. 

 \ Geog. och Pal. Iakttag. Eophytonsandstenen i vestergotland Kongl. Svenska 

 Yet. Akad. Handl., vol. ix, No. 7, 1871. 



