PLATE IX. 



Page. 



KUTORGINA PROSPECTKNSIS 19 



Fig. 1. Dorsal valve, enlarged to three diameters, 

 la. Ventral valve equally enlarged. 

 1 6. Restored outline of the two valves united. 



STENOTHECA ELOKGATA 23 



Fig. 2. Upper side, enlarged to three diameters. 

 2 a. Lateral view of the same specimen. 



LlNGULA? MANTICULA 13 



Fig. 3. Ventral valve, showing the more ovate form. See plate xi, fig. 2. 



KUTORGIXA WHITFIELDI 18 



Fig. 4. Ventral valve, with outline restored, enlarged to two diameters. 

 4 a. Dorsal valve, with outline of convexity below. Natural size. 



PROTOSPONGIA FENESTRATA Salter f 11 



Figs. 5,5 a, &. Three forms of spiculse; 56 is the more unusual form. Natural size. 



SCENEI.LA T CONICA 15 



Fig. 6. Posterior view, showing the elevation ; the slight groove is very much too strong, 

 it is scarcely descernible on the specimen. 



KUTORGINA SCULPTILIS 20 



Fig. 7. Dorsal va've, enlarged to six diameters. See plate i, figs. 7. 7 a, ft. 



ORTHIS EUREKENSIS 22 



Fig. 8. Dorsal valve, enlarged to three diameters. 



80. Ventral valve, similarly enlarged and showing the cast of the muscular scars. 



ACROTRETA GEMMA 17 



Fig. 9. Lateral view, enlarged to four diameters. 



9a. View from above of the same. See plate i, figs. 1 fl-e. 



AGNOSTUS RICHMONDENSIS 24 



Fig. 10. View of the cephalic shield, enlarged to four diameters. 



ACROTHELE f DICHOTOMA 14 



Fig. 11. View of the specimen described, enlarged to three diameters. 



OLENELLUS IDDIMGSI 28 



Fig. 12. View of the type specimen, enlarged to two diameters. 



AGNOSTUS BIDENS 26 



Fig. 13. Cephalic shield, enlarged to four diameters. 



13 a. Small caudal shield associated with the above, enlarged to five diameters. 



AGNOSTUS SECLUSUS ^ 



Fig. 14. Cephalic shield, enlarged to four diameters. 



