explanation of plates 325 



Explanation of Plates 

 Plate 18. — Fossils from the Anisdcn Formation 



Composlta trinuvlea (Hall) 



Figures 1 and 2. Pedicle valves of two average individuals. 



Figures 3 and 4. Brachial views of conjoined valves of average individuals. 



Figure 5. Side view of an average specimen. 



Lod-onvma loorthcnl Weller 



Figure 6. View of an imperfect specimen (X2). 



i^pirifcr pcUansis Weller 



Figure 7. Brachial view of conjoined valves of an average specimen. 



Figure 8. Posterior vie^^• of a long hinge-lined specimen. 



Figure 9. Exterior of a pedicle valve of a long hinge-lined specimen. 



Spirifer welleri n. sp. 



Figure 10. Brachial view of conjoined valves. 

 Figure 11. Front view of a small specimen. 

 Figure 16. Exterior view of a pedicle valve ( X ^ ) . 



Pugnoidcs ottumiva (White) 



Figure 12. Front ^dew of an average specimen. 



Figuties 13 and 14. Brachial and pedicle views of the same specimen. 



Ortonia cf. hlatchlcyi 0. and B. 



Figure 15. Specimen in sinus of SpiHferina hrowni. 



Spirit erina hroivnl n. sp. 



Figure 15. P'ront vie\A' of an average specimen. 

 Figure 17. Brachial view of an average specimen. 



Tvfrucumcra su'bcuncata (Hall) 



Figure IS. Exterior of pedicle valve. 



Vhonetcs vlivsterensis Weller 



Figure 19. Exterior of a pedicle valve. 



Eumetria verneuiliana Hall 



Figure 20. Brachial view of conjoined valves of a small, imperfect speci 



men. 

 Figure 21. Pedicle view of a larger specimen. 



Mevkella anisdenensis n. sp. 



Figure 22. Brachial view of conjoined valves of an imperfect specimen. 



Figure 23. Pedicle view cut to show septal plates. 



Figure 24. Side view of a perfect specimen. 



Figure 25. Branchial view of conjoined valves of an imperfect specimen. 



Spirifer shoshonensis n. sp. 



Figure 26. Exterior of brachial valve of a small specimen. 

 Figure 27. Exterior of a pedicle valve of a large specim-en. 



