PLATE 12 



PAGE 



Ellipsocephaloides nitela, new species 66 



1. Holotype cranidium (XS)- 



2. Pygidium (X6). 



3. Pygidium with full complement of spines, and cranidium (X3)- 



(See also pi. 11, fig. 13.) 

 Honey Creek limestone; (loc. 12m) 7 miles north of Springer, Arbuckle 

 Mountains, Oklahoma. 

 Ellipsocephaloides vionscnsis, new species 66 



4. Holotype cranidium (XS)- 



5. 6. The pygidium (X3)- 



Lyell formation; (loc. 64f) Mons Glacier, 50 miles northwest of Lake 

 Louise, Alberta. 

 Ellipsocephaloides silvestris, new species 64 



7. Well-preserved pygidia (X 5)- (See also pi. 11, fig. 3.) 



Honey Creek limestone; (loc. 91b) West Timbered Hills, Arbuckle 

 Mountains, Oklahoma. 

 Calyptonima typicale, new species 38 



8. Cranidium (X4)- 



9. Holotype cranidium ( X 4) • 



Red Lion formation; (loc. i5oe) Boulder Creek, i mile north of Prince- 

 ton, Montana. 

 Ellipsocephaloides dcclivis, new species 67 



10. Cranidium (X4)- 



11. 12. Dorsal and side views of the holotype cranidium (X 5)- (See 



also fig. 13- ) . 

 Plcthometopiis albertensis, new species 47 



13. Holotype cranidium, with cranidia of Ellipsoceplialoides declivis 

 (see figs. 10-12) and Chariocephalus viaqnns (see pi. 2, fig. 15). 



(X4.) 

 Lyell formation; (loc. 20J) Tilted Mountain Brook, 93 miles east of 

 Lake Louise, Alberta. 

 Maryvillia zvyomingensis ( Resser ) 67 



14, 15. Dorsal and side views of the holotype pygidium (X i-S)- 

 Pilgrim formation ; Dead Indian Creek, Clark Fork, Absaroka Range, 



Wyoming. 

 16, 17. Side and dorsal views of an exfoliated pygidium (X i-S)- 



18. Partially exfoliated cranidium (X i-S)- 



Pilgrim formation; (loc. 4r) Suce Creek, Mount Delano, Snowy Range, 

 Montana. 



19. Cranidium (X i-S)- 



20. Pygidium (X 1.5). 



Pilgrim formation; (loc. iSig) mouth of Clark Fork River, Absaroka 

 Range, Wyoming. (See also pi. 14, fig. i.) 

 Maryvillia violaensis, new species 68 



21. 22. Dorsal and side views of a cranidium. (21, X i-5; 22, X 3-) 



23. Partially exfoliated cranidium (X2.5). 



24. Partially exfoliated pygidium (X i-5)- 



25. 26. The holotype pygidium (X i-S)- 



Maurice formation; (loc. 151k) Labarge Creek, near Viola, Uinta 

 County, Wyoming. • 



Maryvillia titahensis, new species 68 



27, 28. Dorsal and side views of the cranidium (X2). 



29. Libragene (X2). 



30. Hypostoma (X 5)- 



31. Holotype pygidium (X i-S)- 



32. Incomplete pygidium (X i-S)- 



Weeks formation; (loc. 32w) Fandango Spring Canyon, Dugway 

 Range, Utah. 

 Maryvillia marjumensis, new species 68 



33. Hypostoma (X 3)- 



34. Holotype pygidium associated with an exfoliated cranidium 

 (X1.5). 



35. Associated cranidium and pygidium (X i-S)- 



Weeks formation; (loc. 3oi) 5 miles south of Marjum Pass, House 

 Range, Utah. 

 Maryvillia loperi, new species 70 



36. Cranidium (X i-5)- 



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



Sawatch formation; (loc. 6a) Taylor Peak, 4 miles south of Ashcroft, 

 Colorado. 



121 



