58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



DESCRIPTION OF PLATE 8 



cr. Central ring. 



p. Digitate tentacle, 

 re. Radial canals. 



s. Stomach. 



PAGE 



Peytoia nathorsii Walcott 56 



Fig. I. Subumbrella view of the type specimen of the genus and 



species. Natural size. The four large lobes are marked X. 



U. S. National Museum, Catalogue No. 57538. 



A portion of an annelid, Ottoia proliUca, n. g. and n. sp., is 

 shown above the medusa. 

 2. Subumbrella view of a second specimen that differs in detail 

 from the specimen represented by figure i. It also shows 

 the short spines about the oral aperture more clearly. Nat- 

 ural size. U. S. National Museum, Catalogue No. 57539. 

 Both specimens illustrated are compressed in the shale and show no traces 

 of canals or other portions of the medusa within the subquadrate central 

 area. 



Eldonia ludivigi Walcott (see also text fig. 5 and pis. 9-12) 46 



Fig. 3. An individual preserved as a thin film in the shale. Natural 



size. U. S. National Museum, Catalogue No. 57540. 

 This shows a digitate tentacle (p) and radial canals (re) extending to and 



beyond the central stomach (s). The peripheral margin of the umbrella is 



not definitely outlined. Traces of the radial canals are seen crossing the 



stomach on the left side. 



A small individual compressed so as to give a partial side view, is shown 



on the left. This preserves traces of radial canals and stomach. 



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

 Cambrian ; dark siliceous shales in the Burgess shale of the Stephen forma- 

 tion 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. 



I 



