INDEX 435 



PAGE 



Acrothelc (RedUchella), new subgenus 89 



classification of 142, 146 



compared with Acrothele 90 



Acrothele coriacea 89 



Botsfordia 90 



evolution of pi. 11 (pp. 140-141) 



gramilata, compared with Acrothele hella punctata 83 



compared with Acrothele yorkensis 89 



mentioned 83 



Acrothelinse, classification of 142 



defined 146 



Acrothyra, classification of 142, 146 



evolution of pi. 11 (pp. 140-141) 



minor, stratigraphic position and association 198 



Acroircta, apical callosity in 154 



classification of 142, 146 



evolution of pi. 11 (pp. 140- 141 ) 



mentioned 93 



attenuata, stratigraphic position and association 179, 180, 181 



bcUatula, new species 93. pi- 9, figs. 4, 40-^ 



compared with Acrotreta deHnita 94 



Acrotreta sagittalis 94 



stratigraphic position and association 179 



claytoni, stratigraphic position and association i8g 



curvata, compared with Acrotreta ulrichi 96 



definita, compared with Acrotreta bellatula 94 



compared with Acrotreta rudis g6 



depressa, compared with Acrotreta rudis 96 



stratigraphic position and association 210 



idahoensis, compared with Acrotreta marjiimensis 94 



stratigraphic position and association 177 



idahoensis alta, stratigraphic position and association 193 



idahoensis sulcata, stratigraphic position and association 198 



kutorgai Walcott, in synonymy 95 



marjiimensis, new species 94, pi. 9, figs. 2 and 2a 



compared with Acrotreta idahoensis 94 



Acrotreta neboensis 94 



stratigraphic position and association 179 



neboensis, compared with Acrotreta marjiimensis 94 



ophirensis, compared with Acrotreta ophirensis descendens 95 



stratigraphic position and association : 178, 180 



ophirensis descendens, new variety 95, pi. 9, figs, i and la 



compared with Acrotreta ophirensis 95 



stratigraphic position and association 178 



primccva, associated fossils listed 85 



stratigraphic position and association 184 



pyxidicula, stratigraphic position and association 180, 198 



