XLI. Left Mandible of Allognathosuchus riggsi. 



XLII. Fig. 1. Sa = Shale Containing Lecthaylus gregarius and 

 Associated Fauna. Sb = Shale Containing Only Mono- 

 graptus vomerinus. 

 Fig. 2. Photograph Showing Interstratification of 

 Shale and Dolomite. 



XLIII. Lecthaylus gregarius Weller. 



XLIV. Figs. 1-3. Lecthaylus gregarius Weller. 

 Fig. 4. Protoscolex ruedemanni sp. nov. 

 Figs. 5, 6. Incertae sedis. 

 Fig. 7. Orbiculoidea sp. 



XLV. Fig. 1. Dictyonema retiforme (Hall). 



Fig. 2. Dictyonema crassibasale Gurley. 

 Figs. 3, 4, 6, 8. Desmograptus micronematodes 



(Spencer). 

 Fig. 5. Dictyonema teneUum Spencer. 

 Fig. 7. Palaeodictyota bella (Hall and Whitfield). 

 Figs. 9-14. Monograptus vomerinus (Nicholson). 



XLVI. Plastral Aspect of Podocnemis olssoni sp. nov. 



XLVII. Carapacial Aspect of Podocnemis olssoni sp. nov. 



No. 1 



Fig. 1. 

 Fig. 2. 



No. 2 



Fig. 1. 

 Fig. 2. 



No. 3 



Fig. 1. 



No. 4 



Fig. 1. 



Fig. 2. 



Fig. 3. 



Fig. 4. 



Fig. 5. 



Fig. 6. 



Fig. 7. 



Fig. 8. 



Fig. 9. 



TEXT FIGURES 



Page 



Diagram of Linthia variabilis 2 



Diagram of the Floscelle of Cassidulus intermedins . 3 



Section of Metarhinus Beds, as Exposed in the North 



Wall of White River 20 



Panoramic Section of the Amynodon Beds, from 



Kennedy's Basin to White River Canyon .... 21 



Diagrammatic Figure of a Trilobite 44 



Macropetalichthys rapheidolabis 94 



Macropetalichthys rapheidolabis 97 



Macropetalichthys rapheidolabis 101 



Macropetalichthys rapheidolabis 104 



Macropetalichthys rapheidolabis 110 



Macropetalichthys rapheidolabis Ill 



Macropetalichthys rapheidolabis 117 



Macropetalichthys rapheidolabis 128 



Macropetalichthys rapheidolabis 133 



vii 



