NO. 3 MIDDLE CAMBRIAN FOSSILS FROM IDAHO RESSER II 



EXPLANATION OF PLATE 



Page 



Fig. I. Urotheca sampsoni, new species 5 



Portion of a specimen. Holotype, X 2. 



Fig. 2. Margaretia angnstata, new species 4 



Portion of the holotype, X 2. Top portion is of the outside ; 

 lower portion, the impression. 



Figs. 3-5. Acrotrcta nitcns, new species 6 



3, 4. Ventral valves, X 4- 

 5. Dorsal valve, X 4- 



Figs. 6, 7. Acrothclc speciosa, new species 5 



Two ventral valves, X 2. 

 Figs. 8-11. Pagetia jossula, new species 6 



8, II. Cranidia, X 4- 



9, ID. Pygidia and a good cranidium, X 4- 



Fig. 12. Sch'istometopus typicalis, new species 10 



Holotype cranidium. 

 Figs. 13-15. J^amixeinella idahocnsis, new species 9 



13. A cranidium. 



14. Pygidium showing the spines. 



15. Cranidia and pygidium. 



Figs. 16, 17. Agnostus botui-crcnsis, new species 6 



16. A good cranidium, X 4- 



17. Holotype pygidium, X 4- 



Fig. 18. Lingiilella idahoensis, new species 5 



Interior of a ventral valve, X 4- 

 Figs. 19-21. Ufia curio Walcott 9 



19, 20. Cranidia. 



21. Pygidium referred to the species, X 4- 



Figs. 22, 23. Oryctoccphalus tvalcotti, new species 9 



22. Cranidium referred to the species, X 4- 



23. Holotype pygidium. 



Figs. 24-26. Albertella sampsoni, new species 6 



24. 25. Two cranidia. 



26. Holotype pygidium. 



Figs. 27-30. Zacauthoides sampsoni. new species 10 



27. A small cranidium, X 4- 



28. The holotype. 



29. A large pygidium. 



30. A small cranidium, X 2. 



Figs. 31-35. Elrathia sampsoni, new species 8 



3i> 32, 35. Cranidia of various sizes. 



33. Holotype cranidium (see also fig. 58). 



34. Libragene. 



Figs. 36-40. Elrathia idahocnsis, new species 8 



36-38. Cranidia of several sizes. 



39. Holotype cranidium, X 2. 



40. Entire individual. 



