PLATE XXV. 



Bellerophon Thalia. 



Puge 106. 

 Pijf. 1. Dorsal view of » Bpecimen slightly compressed, and soraewhat lengthened in form. 

 Fig. 3. An obliquply compressed specimen, showing the small umbilicus in an internal cast, and preserving 



some remains of surface stiiie. 

 Fig. 3. A laterally coinpi-esaed specimen. 



Bellerophon ACUTILIRA. 



I'age 106. 

 Fig. 4. Latei-al view of a compressed siiecimen eularffcd to two diameters, showing the surface stria acutely 



rccurveil. 

 Fig. 5. Doi-sal view of a small specimen which preserves the shell on the outer part of the volution. 

 Figs. 6, 7, 8. Three views of a large, nearly perfect specimen, retaining the shell with surface-markings. 



Bellerophon M.£ra. 



Pngo 119. 

 Fig. 9. Oblique latei-al ^-iew of a specimen, showing the i-ecurving of the lip over the vimbilicus. The cast 



retains faint marks of the surface charactera. 

 Fig. 10. A 8i>ecimpn showing the form of the aperture and reflection of the lip over the sides of the shell. 



Tliis and the following tigs. 11-14 are from gutta-percha impressions in the natural mold. 

 Fig. 11. A specimen showing the sui-face charactere and the form of the shell. 

 Fig. 12. A similar specimen compressed, with coarser structure. 

 Fig. 13. Lateral view of the specimen fig. 11. 

 Fig. 14. A 8i>ecimen enlarge<l two diametej-s, showing the surface characters and form of the shell. 



Bellerophon obsoletus. 



Fig. 15. Dorsal view of a specimen as obtained by a gutta-percha cast in the natural mold. The surface 

 strite make an abrupt retral curve in the centre of the shell. 



Bellerophon orenistria. 



Piige 116. 

 Fig. 16. Dorsal view of a specimen enlarged four diameters. 

 Fig. 17. A specimen enlarged three diameters. 

 Fig. 18. Doi-sal view of a specimen partially imbedded in the rock ; enlarged to four diameters. 



Bellerophon M.£ra. 



PaKf 119. 

 Fig. 19. Dorsal view of a cast, marked only by the sharp doi-sal carina. ' 



CrRTOLITES (Cyrtonella) PILEOHTS. 



Page 145. 



Figs. 20-22. Thi-ee views of the internal cast of a specimen of the usual form. Fig. 20 shows the impi-essioa 



of a fold on the left side of the postei-ior lip. 

 Fig. 29. Dorsal view of a specimen preserving the shell. 



Ctrtolites (Ctbtonblla) MITELLA. 



Page 123. 

 Figs. 23, 25. Ijiteral and dorsal views of a specimen with the shell partially removed. 

 Fig. 24. The ajiertnral side of a cast, showing a sinuosity or fold of the lip on the right side. 

 Figs. 26, 27. Two views of the typical specimen, an intemal cast, with the doi-sal carina strongly marked. 

 Fig. 28. Enlargement of the surface from the side of a specimen which preserves the shell. 



