PLATE X. 



PAGE 



Figs. 1-3. Athyris subquadrata Hall 472 



1 and 2. Dorsal and front views of a specimen of the prevailing form. 

 3 Dor.-al view of a specimen wi h a more strongly marked fold. 



Fig. 4. Schi'zodus ChESTEREnSIS M. and W 474 



4. View of a left valve, from Maxville, Ohio, formerly identified an 1 labeled by F B. 



Meek. 



Fig. 5. Pinna Maxvillensis Whitf. 474 



5. View of a left valve slightly restored at the apex. 



Fig. 6. Allorisma Andrewsi Whitf. 475 



6. View of a right valve Irom Newtonville, Ohio. The figure is slightly restored on 



the borders. 



Figs. 7-8. Allorisma maxvillensis Whitf. 475 



7. View of a right valve, natural size. 



8. View of a specimen retaining bbth valves, one of which is slightly larger than the ^ 



other, perhaps accidentally so. 



Figs. 9-11. Straparollus similis M. and W 476 



9-11. Lateral vertical and basal views of a specimen showing the irregularly ex- 

 panded carinatirn on the m ddle of the shell. 



Fig. 12. Holopea Newtonensis Whitf. : 477 



12. Side view of the specimen from which the description was drawn. 



Fig." 13. Polyphemopsis melanoides Whitf. 478 



13. View of a specimen showing the form and proportions. 



Fig. 14. Macrocheilus subcorpulentus Whitf. 478 



14. View of the aperture. 



Figs. 15-16. Naticopsis ziczac Whitf. 477 



15 audit). View of the bick o f the shell, natural size and enlarged, showing the pecu- 

 liar surface markings. 



Figs. 17-19. Bellerophon alternodosus Whitf , 479 



17-19. Three views of the same specimen, which is slightly imperfect. 



Figs. 20-21. Bellerophon subl^vis Hall 479 



20 and 21. Back and profile views of a specimen from which the shell is mostly re- 

 moved. The auriculations being only partially preserved and the front removed. 



Fig. 22. Nautilus ( Temnocheilus ) spectabius M. and W 480 



22. Lateral view of the inner septate portion of a specimen from near Rushville, Ohio, 

 showing the character of the shell. 



Fig. 23. Nautilus pauper Whitf ; 481 



2.1. View of the specimen described showing the outer chamber and the impression of 

 the inner coils. 



