NO. 5 UPPER CAMBRIAN TRILOBITES RESSER II5 



PLATE 6 



PAGE 



Cholopilus nevadensis, new species 36 



I, 2. Dorsal and side views of holotype cranidium (X-2.5). 

 Hamburg limestone; (loc. 23d) near Hamburg Mine, Eureka District, 

 Nevada. 



Illacniints priscus, new species 38 



3, 4. Cranidia. (3. X 3; 4, X 5-) 

 5, 6. Small cranidium (XS)- 



7. Holotj'pe cranidium (X3)- 



Lyell formation; (Iocs. 66j, k) Ranger Canj-on, Sawback Range, 

 Alberta. 



lllacnurns albert ensis, new species 38 



8. Libragene (X 2). 



9. Pygidium (X 2). 



10. II. Dorsal and side views of a partially exfoliated cranidium (X 2). 



12. Holotype cranidium (X2). (See also pi. 14, fig. 18.) 



Lyell formation; (loc. 2od) Tilted Mountain Brook, 9 miles east of 

 Lake Louise, Alberta. 



lllacnurns (?) Sinclair cnsis, new species 39 



13, 14. Dorsal and side views of the holotype cranidium (X2.5). 



15. Two associated cranidia (XS)- 



Sabine formation; (loc. i6t) Sinclair Canyon, Brisco Range, British 

 Columbia. 



Platycolpns qninncnsis. new species 40 



16, 17. Dorsal and side views of the holotype cranidium (X i-5)- 

 Mendha limestone; (loc. "j ) Quinn Canyon Range, Nevada. 



Illaenurus elongatus (Walcott) 40 



18, 19. Side and dorsal views of the holotype cranidium (X 5)- 

 McKay group ; (loc. 232) 2 miles west of Donald, Dogtooth Mountains, 

 British Columbia. 



Platycolpns oklahomcnsis. new species 40 



20, 21. Incomplete cranidium (X i-5)- 



22, 23. Exfoliated pygidium. 



Signal Mountain formation; (loc. 201J) Royer Ranch, Honey Creek, 



Arbuckle Mountains, Oklahoma. 

 24, 25. Side and dorsal views of the holotype pygidium. 

 Signal Mountain formation; (loc. i86s) 4 miles northwest of Ravia, 



Arbuckle Mountains, Oklahoma. 



Platycolpns zvichitaensis, new species 41 



26, 27. Dorsal and side views of the holotype pygidium. 

 28, 29. An incomplete cranidium. 



Signal Mountain formation; (loc. I2g) 2 miles southwest of Signal 

 Mountain, Wichita Mountains, Oklahoma. 



Platycolpns highlandensis, new species 41 



30, 31. Squeeze of the holotype pygidium. 



Mendha limestone; (loc. 88) 7 miles north of Bennett Springs, High- 

 land Range, Nevada. 



Platycolpns sinclairensis. new species 42 



32, 33. Side and dorsal views of a large pygidium. 

 34> 35- The holotype pygidium. 



36. Libragene. 



Sabine formation; (loc. i6t) Sinclair Canyon, Brisco Range, British 

 Columbia. 



Enontioura typicalis, new species 43 



37, 38. Side and dorsal views of the holotype pygidium. 



Mendha limestone; (loc. 88) 7 miles north of Bennett Springs, High- 

 land Range, Nevada. 



