ILLUSTRATIONS 



PLATES 



TO FACE PAGE 



1. Side canyon of the O-shui-ho near Yen-t'6u, Shan-si. ..... 36 



2. The Yang-tzi canyon at Nan-t'ou, Hu-pei 41 



3. Canyon of the T'ai-shan-ho southwest of Shi-pan-k'ou, 



Shan-si 56 



4. Lake Balls and Layer Deposit (Blue-green algae) 118 



5. Lake Balls and Neivlandia 120 



6. Algonkian Algal Flora {N ewlatidia frondosa) 122 



7. " " " (Nezvlandia frondosa) 124 



8.. " " " (Nezvlandia frondosa) 126 



9. " " " (Camasia and Nezvlandia) 128 



10. " " " {Nezvlandia and Collenia) 130 



11. " " " (Weedia and Kinneyia) 132 



12. " " " (Camasia spongiosa) 134 



13. " " " (Collenia undosa) 136 



14. " " " (Collenia undosa) 138 



15. " " " (Collenia) 140 



16. " " " (Cryptosoofi proliferum) 142 



17. " " " (Greysonia basaltica) 144 



18. " " " (Greysonia basaltica) 146 



19. " " " (Copperia tiihiformis) 148 



20. Microscopic cells from recent Blue-green Algge and their 



Algonkian representatives 150 



21. Annehd trails (H elminthoidichnites and Planolites) 152 



22. Belt Terrane Fossils (Beltina danai) 154 



23. Algonkian Algal Flora (Gallatinia pertexa) 156 



24. Cambrian Trilobites (Acrocephalites) 230 



25. " " (Acrocephalites and Alokistocare) . . . 232 



26. " " (Acrocephalites, Menomonia, Dres- 



bachia, Alokistocare, and Amphion) 234 



27. " " (Norzuoodia) 236 



28. " " (Norzvoodia and Millardia) 238 



29. " " " (Crepicephalus) 240 



30. " " (Crepicephalus texanus (Shumard)) 242 



(vii) 



