142 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



DESCRIPTION OF PLATE 22 



PAGE 



Planolites sp. ? 



Fig. I. (Natural size.) Portion of a trail associated with Ottoia pro- 

 liiica (pi. 19) illustrating a very common type of trail in 

 the Burgess shale. U. S. National Museum, Catalogue No. 

 57642. 



WorthencUa cambria Walcott 126 



Fig. 2. (X2.) The type specimen as it occurs flattened on shale'. U. 

 S. National Museum, Catalogue Nos. 57644 and 57645. 



Amiskivia sagittiformis Walcott 112 



Figs. 3 and 4. (X3.) Flattened specimens described in the text. U. 

 S. National Museum, Catalogue Nos. 57644 and 67645. 



Ottoia minor Walcott 129 



Fig. 5. (X2.) An elongated specimen that occurs flattened on the 

 shale. U. S. National Museum, Catalogue No. 57646. 

 6. (X 2.) A small contracted specimen. U. S. National Museum, 

 Catalogue No. 57647. 



All of the specimens illustrated on this plate are from locality (35k) 

 Middle Cambrian : dark siliceous shales in the Burgess shale member of the 

 Stephen formation on the west slope of the ridge between Mount Field and 

 Wapta Peak, one mile (1.6 km.) northeast of Burgess Pass, above Field, 

 British Columbia. 



