PLATE XX. 



r\GE. 



SANGUINOLITES BANDOLPHENSIS Worthen I.'W 



Fig. 1. View of left valve, natural size. 

 Fig. 1 a. Dorsal view of same specimen. 



MODIOLA ILLINOIENSIS Worthen 123 



Fig. 2. View of left valve, natural size. 

 Fig. 2 a. Anterior view of same. 



SCHIZODUS NAUVOOENSIS Worthen 108 



Fig. 3. Cast of left valve, natural size. 



PLEUEOPHOEUS MINIMUS Worthen 121 



Fig. 4. Outline of left valve, natural size. 

 Fig. 4 a. View of same magnified 2. X. 



AVICULOPINNA ILLINOIEN8IS Worthtn 128 



Fig. 5. Lateral view of a specimen partially restored in outline. 

 Fig. 5 a. Profile view of same, both natural size. 



PLEUBOPHOBUS? CHESTEEENSIS Worthen 12S 



Fig. 6, View o' both valves, embedded in the matrix. 



CONOC AEDIUM PAEBISHI Worthen 1 12 



Fig. 7. Lateral view of specimen, natural size. 



BANOUINOLITES? BUBLINGTONENSIS Worthen 12l> 



Fig. 8. View of left valve, natural size. 

 Fig. 8 a. Dorsal view of same. 



SCHIZODUS ULBICHI Worthen llu 



Fig. 9. View of a left valve, natural size. 



MYALINA MONEOENSIS Worthen 1-T 



Figs. 10 and 10 a. View of opposite valves, natural size. 



EDMONDIA VAESOYIENSIS Worthen 121 



Fig. ll. View of left valve, natural size. 

 Fig. 11 a. Dorsal view of same. 



SCHIZODUS BANDOLPHENSIS Worthen !li> 



Fig. 12. Cast in limestone of left valve, natural size. 



