574 INDEX 



PAGE 



Paranaspides 166, 172, 207 



lacustris Smith, discussed 170 



figured, pi. 35, fig. 3 207 



text fig. 3 172 



Park shale 17 



Pheronema, compared 323 



Phycoidella stichidifera 224 



Phyllocarida, relation of trilobite to 162 



Phyllopod, relation to trilobite 168 



Pilgrim limestone 17 



Pirania muricata Walcott, described 298 



figured, pi. 79, figs. 1, la-e 353 



text-figs. 4, Afl 299 



Pirania Walcott, described 298 



Flatyceras lais Walcott 472 



Potosi formation 468 



Pre-Devonian formations of Alberta and British Columbia, Canada, results 



of field reconnaissance of 479 



Progression, trilobites' method 124 



Protichnites, tracks discussed 174 



Proctor formation 468 



Protorthis billingsi (Hartt) , compared 525 



iones, new species, Ozarkian 479 



compared 504 



described 503 



figured, pi. 113, figs. 1-7 541 



porcias, new species, Ozarkian, described 504 



figured, pi. in, figs. 10-11 539 



Protospongia, compared 310 



delicatula named 302 



erixo Walcott, figured, pi. 79, figs. 2, 20- c . . 353 



fenestrata Salter, described 304 



figured, pi. 80, figs. 1, \a, b, 2 354 



? , spicules referred to 331 



hicksi Hinde, described 307 



figured, pi. 80, figs. 3, 3a, b 354 



? minor, compared 305 



? minor var. distans, compared 305 



mononema, named 302, 303 



figured, text-figs. 5, 6 303 



polynema, named 302 



Salter, described 301 



tetranema, named 302, 303 



Protospongidae Hinde, family characterized 301 



Ptarmigan formation 1, 2, 14 



fauna 22, 24 



Peak section 5 



time 21 



Ptychaspis eurydice Walcott 473 



