EXPLANATION OF PLATE VIIL 



{Figures all of natural size.) 



Spirifera Pedroana, Uartt, sp. nov., page 237. 



I, 4, 5 and 17. Ventral valves of large size. In fig. 4 the dental plates 



are seen to be rather long. 

 3, 9, 13, 16 and 18. Venti-al valves of medium size. 

 14. Small ventral valve. 

 19. Ventral valve, somewhat larger than fig. 14, inclined slightly forward, 



so as to show the hinge area in part. 

 8. Hinge area of ventral valve, with the margins of the fissure partly 



broken away. 

 3 and 7. Large dorsal valves. 

 () and 20. Dorsal valves of medium size. 



Spirifera Elizae, Hartt, sp. nov., page 239. 



15 and 21. Ventral valves. Fig. 21 is the most perfect specimen yet 

 found, while fig. 15 is much broken, and its dental plates are slightly 

 curved. 



Spirifera Yalenteaiia, Hartt, sp. nov., page 241. 



II. An interior mould of the ventral valve, the only specimen of this 

 species obtained. 



Rhynclionella (Stenocisma,) dotiS; Hall, page 246. 



10 and 12. Dorsal valves. In fig. 12 the margins of the valve are par- 

 tially obscured by the rock, in which it is embedded. 



(All of the above specimens are interior moulds.) 



