PAGE 



Rome formation, Tennessee, Aliddle Cambrian localities 2,^7 



Middle Cambrian locality 9 371 



rotundatus, see Bathyuriscus. 



St. Lawrence formation, Wisconsin, Upper Cambrian localities 78, 85 406 



St. Lawrence-Newfoundland area, compared with Canadian Rocky Moun- 

 tain region 30S 



Salem, New York, Lower Cambrian locality 43a 317 



Saltcrclla, in association with Olenellus 321 



pulchella Billings, from Point Levis limestones 329 



listed 321 



rugosa Billings, listed 321 



Saukia pepinensis ( Owen ) , listed 409 



Scenella varians Walcott, listed 322, 353 



Secret Canyon, Nevada, Middle Cambrian locality 55b 369 



sencctus, see Corynexochus. 



Shan-tung, China, Middle Cambrian localities Ci, C2 366, 367 



Middle Cambrian locality C4 361, 366 



localities C19, C57 366 



C24 368 



Shooks Gap, Tennessee, Middle Cambrian locality 10 371 



Simpson Spring. Utah, Middle Cambrian locality lis 371 



Sinuopea, 3 undt. spp., listed 409 



Sixteen Mile Canyon, Montana, Middle Cambrian locality 621 362, 425 



Solenopleura, unlike Lisania 404 



tumida Walcott, listed 317 



Spence shale, Wasatch Canyon, L^tah, Middle Cambrian locality 



556 335, 341, 378 



Idaho, Middle Cambrian locality 55c 336, 341, 350, 351, 363, 408 



spinulosus, see Corynexochus. 



Stenotheca elongata Walcott, listed 317, 353, 369 



Stenotheca rugosa (Hall), listed 317 



Stephen formation, Alberta and British Columbia, Middle Cambrian locali- 

 ties 364 



Ogygopsis zone, Middle Cambrian locality 14s 325, 346, 347, 351 



Middle Cambrian locality 35k 325, 347, 408 



locality 57J 347 



58J 335 



58r 378 



stephenensis, see Corynexochus. 

 stolicskai, see Bathyuriscus. 

 suecicus, see Dolichonietopus. 

 sylla, see Bathyuriscus (Poliella). 



Symphysurus Goldfuss, compared with lUanurus 405 



Syntrophia ? unxia Walcott, listed 403 



Swinnerton, cited 407 



Tapeats sandstone, Arizona, Middle Cambrian locality 74 374 



Teton Range, Wyoming, Middle Cambrian locality 4d 391 



