Contributions to Invertebrate Palaeontology. 617 



Spirifera contracta M. and W. Page 583. 

 Fig. 17. Dorsal view of the type specimen from the Chester limestone of 



Illinois, introduced for comparison. 

 Figs. 18 and 19. Dorsal and profile views of a specimen from the Maxville 



limestone, at Newtonville, Ohio. 



Spirifera Rockymontana (?) Marcou. Page 584. 



Fig. 20. View of a ventral valve showing rather stronger plications than most 

 individuals. 



Terebratula tprgida Hall. Page 586. 

 Figs. 21 and 22. Dorsal and profile views of a specimen from Newtonville, 

 Ohio. The figures are slightly restored on the lower part. 



PLATE XIV. 



Athyris subquadrata Hall. Page 585. 



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

 Fig. 3. Dorsal view of a specimen with a more strongly mai'ked fold. 



ScHizoDus Chesterensis M. and W. Page 587. 



Fig. 4. View of a left valve, from Maxville, Ohio, formerly identified and 

 labelled by F. B. Meek. 



Pinna Maxvillensis Whitf. Page 586. 

 Fig. 5. View of a left valve sliglitly restored at the apex. 



Allorisma Andrewsi Whitf. Page 588. 



Fig. 6. View of a right valve from Newtonville, Ohio. The figure is slightly 

 restored on the borders. 



Alloeisma maxvillensis Whitf. Page 588. 



Fig. 7. View of a right valve, natural size. 



Fig. 8. View of a specimen retaining both valves, one of which is slightly 

 larger than the other, perhaps accidentally so. 



Straparollus similis . ard W. Page 589. 

 Figs. 9-11. Lateral, vertical, and basal ts of a specimen showing the 

 irregularly expanded carination on the middle of the shell. 



HoLOPBA Newtonensis Whitf. Page 591. 

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

 Annals N. Y. Acad. Sct., V, Feb. 1891.— 41 



