VIU ILLUSTRATIONS 



23. Middle Cambrian Annulata (Canadia and Aysheaia) 144 



24. Middle Cambrian Crustaceans (Neolenus, Ptychoparia, 



Mollisonia, and Tontoia) 208 



25. Middle Cambrian Crustaceans {Marrella) 210 



26. " " " {Marrella) 212 



27. Middle Cambrian Crustaceans (Burgessia, Waptia, and 



Opahinia) 214 



28. Middle Cambrian Crustaceans {Opahinia, Nathorstia, and 



Naraoia) 216 



29. Middle Cambrian Crustaceans. {Molaria, Habelia, and 



Yohoia) 218 



30. Middle Cambrian Crustaceans {Bidentia, Emeraldella, and 



Burgessia) 220 



31. Middle Cambrian Crustaceans {Hymenocaris and Lean- 



choilia) 222 



32. Middle Cambrian Crustaceans {Hymenocaris, Fieldia, and 



Hurdia) 224 



33. Middle Cambrian Crustaceans {Carnarvonia and Tuzoia) . . 226 



34. " " " {Hurdia, Odaraia, and Ano- 

 malocaris) 228 



35. Brachiopods and Trilobites {Lingulella, Obolus, and Cera- 



topyge) 236 



36. Trilobites ( Olenopsis) 248 



T)'/'. Cryptoaoon prolifcrum Hall 280 



38. Trail of Annelid {Climactichnites) 282 



39. " " " {Climactichnites) 284 



40. " " " {Climactichnites) 286 



41. Potsdam-Hoyt Fauna {Lingulella, Triblidium, Pelagiella, 



and Matherella) 288 



42. Potsdam-Hoyt Fauna {Matthevia) 290 



43. " " " {Palceacmcca, Hyolithellus, Hyoli- 

 thes, Lonchocephalus, Agraulos, Ptychaspis, and Pty- 

 choparia) 292 



44. Potsdam-Hoyt Fauna {Dikelocephalus, Conokephalina, 



Pagodia, and Ptychoparia) 294 



45. Legs of Trilobites {Neolenus serratus) 296 



46. Tracks of Trilobites {Protichnites) 298 



47. " " " {Protichnites) 300 



48. " " " {Protichnites) 302 



49. " " " {Protichnites) 304 



