490 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



PAGE 



Siphonotreta, classification of 142, 146 



compared with Dearbornia 80 



evolution of pl- n (PP- 140-141) 



mentioned 78 



Siphonotreta ? dubia, mentioned 300, 315 



stratigraphic position and association 189 



Siphonotretacea, classification of • 142 



defined ^45 



Siphonotretidse, classification of 142 



defined 146 



diagram showing line of descent 140 



distribution in Cambrian strata 140 



number of genera referred to the family 141 



Siyeh limestone, possibly represented in Bow Valley 431 



Smith, E. A., species named after 63 



smithi. see Obelus. 



Smithsburg, fossils from 34° 



Solenoplcura, stratigraphic position and association 175, 176, 178, 180, 192 



igg, 208 



Spence, R. S., discovery of Spence shale by 5 



Spence Gulch, fossils from 26, 30 



Spence Shale, defined 8 



discovery of 5 



fossils from 26, 30 



Blacksmith Fork, correlated 171 



section of 197-198 



House Range, correlated 171 



section of 183, pl. 17 



spencei, see Nisusia (Jamesella). 



spinosus, see Paradoxides and Zacanthoides. 



Spirifer, stratigraphic position and association 200 



Splanchnocoele, defined 158 



Spondylium, defined and discussed 159 



spurri, see Acrothele. 



Stansbury Range, Utah, fossils in 69, 91 



Stenotheca elongata, stratigraphic position and association 189, 213 



Stenotheca cf. elongata, mentioned 300, 315 



Stenotheca rugosa, mentioned 300, 315, 341 



Stenotheca cf. rugosa, stratigraphic position and association 189 



Stenotheca zvheeleri, stratigraphic position and association 210 



Stenotheca sp. undt., stratigraphic position and association 199 



Stephen formation, defined 3 



fossils from 17 



Britigh Columbia, fossils in 102 



Castle Mountain, view showing pl. 20, fig. 2 



Mount Bosworth, correlated 171 



section of 209-212 



stephenensis, see Karlia. 



