index 577 



PAGE 



" Schizopods," comparison with trilobite 173 



Schuchert, Dr. Charles 366, 379, 380, 416 



Sentinelia Walcott, described 289 



draco Walcott, described 290 



figured, pi. 72, figs. 1, la 346 



Shaffcria Walcott, new genus, described 71 



cisina Walcott, described 71 



figured, pi. 11, figs. 8, 80 in 



Sidneyia inexpcctans 429 



Silicispongiae, sub-class characterized 269 



Sodalitia allani Walcott ■ 471 



Sollas, W. J., cited 313 



Species, Cambrian. . .480, 481, 482, 484, 487, 488, 495, 496, 498, 499, 500, 



501, 505, 507, 513. 514, 520, 521, 522 



Ordovician 480, 487, 492, 503, 504 



Ozarkian.. .480, 482, 483, 484, 485, 486, 489, 491, 492, 493, 494, 495, 

 496, Soi, 502, 503, 504, 506, 508, 509, 511, 512, 



513, 5i6, 517, 5i8, 519, 520, 521, 527, 529, 531 



Sphacrocodium Rothplets, genus named » 242 



? cambria Walcott, new species, described 243 



figured, pi. 59, fig. 2 243 



? pr occur sor Walcott, new species, described 243 



figured, pi. 59, figs. 1, la-c 260 



Spiral branchiae 407 



Sponges, manner of preservation 220 



Stephanella sancta, compared 292 



Straparollina isadcs Walcott 472 



milo Walcott 474 



sp. undt 473 



Straparollus ? lavinia Walcott 473 



Structure of exopodite of Calymcne and Ceraurus 412 



Sub-genus Westonia Walcott 523 



Suberitidae, family named 291 



Sullivan formation (Cambrian, Upper) 461 



fauna 461 



Supplementary notes 377 



Symphysurina 458, 470 



canadensis Walcott 474 



entcllus Walcott 473 



eugenius Walcott 473 



eurekensis Walcott 467 



lynxensis Walcott 474 



major Ulrich (Mss.) 467 



mesleri Ulrich (Mss.) 467 



numitor Walcott 474 



perola Walcott 474 



spicata augusta Walcott 474 



spicata major Walcott 474 



spicata Ulrich (Mss.) 467 



spicata Walcott 474 



