PLA.TE IX. 



Page. 

 Fig. 1. Spirifer scobina 90 



1. Dorsal view of a mature epecitnen, with the granules of the surface worn off. 

 1 a. Side view of same. 



1 6. Ventral view of same. 



1 c. A portion of the granular surface magnified. 



Id. A cardinal view of a ventral valve, showing area and foramen. 



Fig. 2. Spirifer cameratus? 91 



2. Ventral view of an imperfect specimen. 



2 a: Side view of same. 



Fig. 3. Athyris Roissyi 82 



3. A side view of a large specimen accidentally compressed. 



3 a. Ventral view of same. 



3 h. Dorsal view of same. 



Fig. 4. Athyris? persinuata 81 



4. An antero-ventral view, showing the profound sinus of the front. 



4 a. A dorsal view of same ; a part of the shell being removed so as to show the 



muscular scars. 



4 1). Side view of same, with beak and contiguous parts broken away. 



Fig. 5. GONIATITES GONIOLOBUS 98 



5. A profile view of an internal cast, with the body-chamber broken away. 



5 a. Side view of same. 



5 6. Diagram of lobes and sinuses of one of the septa, natural size. 



Fig. 6. Spirifer OPiMus?. A ventral view 88 



Fig. 7. AVICULOPECTEN Utahensis 95 



7. A left ? valve, natural size. 



7 a. A portion of the surface of same, magnified to show the minute, crowded, concentric 



strisB. 

 7 6. A mould of a larger individual in the rock. 

 7 c. A mould of a small right valve of apparently the same. 

 7 d. A cast of another specimen of same, differing a little in form. 



