NO. 3 CAMBRIAN AND OZARKIAN TRILOBITES 63 



PAGE 



Genus Symphysuriiia Ulrich 108 



Syuiphysurina ? entella, new species, Ozarkian (Mons) 112 



Symphysurina eugenia, new species, Ozarkian (Mons) 113 



Symphysurina spicata Ulrich MSS., Ozarkian (Goodwin) 113 



Symphysurina zuoosteri Ulrich MSS., Ozarkian 115 



Genus Taenicephalus Ulrich and Resser 116 



Taenicephalus shumardi (Hall), Upper Cambrian (Franconia) . . 117 



Genus Tostonia Walcott 117 



Tostonia iole (Walcott), Middle Cambrian 117 



Genus Uccbia Walcott 118 



Ucebia ara Walcott, Upper Cambrian 1 18 



Genus Utia Walcott 118 



Utia curio Walcott, Middle Cambrian 119 



Genus Vistoia, new genus 121 



Vistoia prisca, new species. Middle Cambrian (Gietang) 122 



Genus Wilbernia Walcott 123 



Wilbernia pero (Walcott), Upper Cambrian (Wilberns) 124 



Genus Xenostegium Walcott 124 



Xenostegium alhertcnsis, new species, Ozarkian (Mons) 125 



Xenostegium belcmnurum, (White), Canadian ? 125 



Xenostegium douglasensis, new species, Ozarkian (Mons) 125 



Xenostegium euclides, new species, Ozarkian (Mons) 126 



Xenostegium ? eudocia, new species, Ozarkian (St. Charles) 126 



Xenostegium, goniocercum (Meek), Canadian ? 127 



Xenostegium kirki, new species, Ozarkian (Mons) 127 



Xenostegium, scho^eldi, new species, Ozarkian (Mons) 127 



Xenostegium shephardi (Raymond), Ozarkian (Mons) 128 



Xenostegium ? sulcatum, new species, Ozarkian (St. Charles). .. . 128 



Xenostegium tanriis, new species, Ozarkian (Chushina) 128 



ILLUSTRATIONS 

 Plates 

 plate facing page 



15. Cambrian trilobites 130 



16. Cambrian trilobites 132 



17. Cambrian trilobites 134 



18. Upper Cambrian trilobites 136 



19. Idahoia 138 



20. Briscoia 139 



21. Symphysurina 140 



22. Kainella — Moxomia^ — Housia 142 



23. Belief ontia — Leiostegium — Moosia 143 



24. Ozarkian trilobites 144 



Text Figures 

 figure page 



12. Belief ontia collicaiia (Raymond) ; corrected drawing of the geno- 



type 72 



13. Holteria problematica (Walcott) ; side outline of the cranidium illus- 



trated in pi. 15, fis:. 17 92 



