PLATE 113. 



Page 



Tig. 1 - 5. Plattceras tortuosum. 472 



1-5. Views of different iiKiividuals (whicli are more or less perfect); gliowing a gradation 



III size. 



Fig. 6. Platyceeas ? 47S 



6. A cast ; tlie siieeimon too imperfect for determination. 



Fig. 7 & 8. Platyostoma ventricosa. 469 



7. Profile of tiie spire of a very large specimen, whicli has been somewhat compressed ver- 



tically. 



8. View of the spire of the same specimen. The surface shows broad nndulations parallel to 



the lines of growth. 



