NO. 3 CAMBRIAN AND OZARKIAN TRILOBITES I33 



PAGE 



Corbinia valida Walcott 82 



Fig. 18. Dorsal view of the single cranidium in the collections. U. S. 

 Nat. Mus., Cat. No. 70244. 



Matrix, limestone. 



Ozarkian, Mons. formation. (Loc. 6sx) : Clearwater Canyon, 

 Alberta. 



Corbinia horatio Walcott 81 



Fig. 19. Dorsal view of the type cranidium, U. S. Nat. Mus., Cat. 

 No. 70245. 



20. Associated free cheek. U. S. Nat. Mus., Cat. No. 70246. 



21. A small imperfect associated pygidium. U. S. Nat. Mus., Cat. 



No. 70247. 



22. Associated cranidium and pygidium. U. S. Nat. Mus., Cat. No. 



70248. 



Matrix, limestone. 



Ozarkian, Mons formation. (Loc. 65x) : Clearwater Canyon, 

 Alberta. 



Maladia amcricana Walcott 105 



Figs. 23, 24. Dorsal and s'de views of the type cranidium. U.-S. Nat. 

 Mus., Cat. No. 70249. 



25. Associated free cheek assigned to this species. U. S. Nat. Mus., 



Cat. No. 70250. 



26. An incomplete associated pygidium with outlines restored. 

 . U. S. Nat. Mus., Cat. No. 70251. 



Matrix, coarse limestone. 



Upper Cambrian, Ovid formation. (Loc. S4x) : Two Mile Canyon, 

 2 miles (3.2 km.) southeast of Malad, Idaho. 



Kingstonia apion Walcott 103 



Figs. 27, 27a. (X 2.) Dorsal view and side outline of the type cra- 

 nidium. U. S. Nat. Mus., Cat. No. 70252. 

 28,28a. (X2.) Dorsal view and side outline of the associated 

 pygidium assigned to this species. U. S. Nat. Mus., Cat. 

 No. 70253. 



Matrix, limestone. 



Upper Cambrian, Maryville formation. (Loc. 127) : 5 miles 

 (8 km.) west of Cleveland, Tennessee. 



Dokimocephalus pernasutus (Walcott) 84 



Figs. 29, 30. Dorsal and side views of the type cranidium. U. S. Nat. 

 Mus., Cat. No. 24608a. 

 31. A nearly complete associated free cheek. U. S. Nat. Mus., Cat. 

 No. 24608b. 



Matrix, limestone. 



Upper Cambrian, Secret Canyon shale. (Loc. 61) : Eureka Dis- 

 trict, Nevada. 



Dokimocephalus gregori Walcott 84 



Figs. 32, 33. Dorsal and side views of this remarkable cranidium. U. S. 

 Nat. Mus., Cat. No. 70254. 



Matrix, limestone. 



Upper Cambrian. (Loc. iie) : Southwest of Potosi, Missouri. 



(AH figures natural size except 27 and 28.) 



