no SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



Class Gephyrea — Quatrefages 127 



Family Ottoidse, new family 128 



Genus Ottoia, new genus 1 28 



Ottoia prolifica, new species 128 



Ottoia minor, new species 129 



Ottoia tenuis, new species •. 130 



Genus BanfUa, new genus 1 30 



Banff ia constricta, new species 130 



Family Pikaidas, new family 131 



Genus Pikaia, new- genus 131 



Pikaia gracilens, new species 132 



Genus Oesia, new genus 132 



Oesia disjuncta, new species 133 



ILLUSTRATIONS 



PAGE 



Plate 18. Miskoia preciosa I34 



19. Genera Ottoia, Selkirkia 136 



20. Genera Pikaia, Oesia 138 



21. Genera IViwaxia. BanfUa 140 



22. Genera IVortheneUa, Amisku'ia. Ottoia 142 



23. Genera Caiiadia, Ayshcaia 144 



INTRODUCTION 



This is the third paper on Middle Cambrian fossils from the 

 Burgess shale member of the Stephen formation of British 

 Columbia. The first was on the Merostomata^ and the second on 

 the Holothurians and Medusse.^ We now have for consideration 

 the annelids. As a rule the annelids have been known only by trails 

 and borings in the muds and sands deposited in the various periods 

 between the Pre-Cambrian Algonkian and the present, and only 

 under very exceptional conditions have any traces of the actual 

 animal been preserved. The most noted discoveries are those in 

 the Upper Jurassic Solenhofen lithographic shales of Bavaria and 

 the Eocene shales of Monte Bolca. Another discovery that has long 

 escaped the attention of authors is that made by Dr. E. O. Ulrich 

 and described by him in 1879.^ These fossils appear to be true seg- 

 mented Polychsetous annelids from the Ordovician shale at Cin- 

 cinnati, Ohio. 



^Smithsonian Misc. Coll., Vol. 57, No. 2, 191 1. 



^ Idem, No. 3. 



^Journ. Cincinnati Soc. Nat. Hist., Vol. i, 1879, pp. 87-91. pi. 4, figs. 1-4. 



