PLATE ^^Yl.—Cmtinmd. 

 Bellerophon trilekatus, juvens ? 



Page 118. 



Fig. 15. A small imperfect specimen, preserving the tricarinate character, with faint marks of revolving 

 striae. 



Fig. 16. The doi-sal side of a specimen exhibiting the tricarinate character, with faint indications of concen- 

 tric undulations. 



Bellerophon nactus. 



Page 121. 

 Fig. 17. The dorsal side of a small specimen which is unusually narrow, with a sharp carina. 

 Fig. 18. A doi"80-l«teral view of a broader and more gibbous specimen. 



Bellerophon M^ra. 



Page 119. 

 A cast of the interior, pi-eserving the dorsal cai-ina and showing the expanded peristome. 

 A specimen partially preserving the shell, from which the surface-markings have been removed by 

 maceration and solution. 



Fig. 21. Lateral view of a large specimen, from which the shell has been partially removed by maceration, 

 and preserving the surface-markings on the outer portion of the volution. 

 Lateral view of a cast of the interior. 



A longitudinal section, showing the inner volutions and the gradual thickening of the columellar 

 lip. See, also, plate 25, figure 10. 



Fig. 19. 

 Fig. 20. 



Fig. 22, 

 Fig. 23 



, Bellerophon Leda. 



Page 120. 

 Fig. 24. A dorso-lateral view of a specimen with a simple dorsal band, without revolving strise, and some 

 incipient longitudinal plications. 



Ctrtolites (Cyrtonella) PILEOLUS. 



Page 125. 

 Fig. 25. A dorsal view of a specimen in which the shell is partially preserved. 



Porcellia Nais. 



Page 127. 

 Fig. 26. A dorsal view of the specimen, showing the mesial band. 

 Fig. 27. An oblique ventral view of the j)receding specimen. 

 Fig. 28. The inner volutions of another individual, showing the fine cancellating strise and lateral nodes. 



