PLATE YIIL 



Cyclonema vabicosa^ ITall, 1871. 



Fig. 1. A young individual, from Cincinnati, Ohio. Collection of Mr. Dyer. 

 Fig. 2. View of a specimen showing the aperture ; one of the specimens originally 



described. From Tennessee. 

 Fig. 3. An outline figure of the aperture of Cyclonema hilix, for comparison with 



the preceding figures. Collection of Mr. Dyer. 



FUSISPIRA TEREBRIF0R3ITS Hall, 1871. 

 Page 230. 

 Fig. 4. View of a specimen of this species. 



F US ISP IRA E LONG ATA Hall, 1871. 

 Page 229. 



Fig. 5. View of the specimen described. 



FuSISPlRA VENl RIlOSA Hall, 1871. 

 Page 229. 



Fig. 6. View of the specimen described. 



Cyrtolites Dykri Hall, 1871. 



Page 230. 

 Fig. 7. Lateral vie-^v of the specimen, enlarged to two diameters. 

 Fig. 8. Dorsal view of the same, showing the form of the aperture. 



BeYRICHIA OCULIFER Hall, 1871. 

 Page 232, 



Fig. 9. Lateral view of a left valve, showing the oculiform tubercle. 



Fig. 10. Profile view of the same, showing the elevation of the eye ; enlarged. 



BeYRICHIA TU3UFR0NS Hall^ 1871. 

 Page 231. 

 Fig. 11. Lateral view of a left valve, enlarged. 



Leperditia {Isouhilijsa) cylindriga Hall, 1871. 



Page 231. 

 Fig. 12. A right valve, enlarged. 



Leperditia {Tsochilina) iiinutissima Hall, 1871. 



Page 231. 

 Fig. 13. View of a left valve showing the nearly central tubercle. 



Proetus parviusculus Hall, 1866. 



Page 223. 

 Fig. 14. View of an entire individual, enlarged to four diameters. 



Dalmania breviceps Hall, 1866. 



Page 223. 

 Fig. 15. View of the upper side of the specimen described. 

 Fig. 16. Profile view in outline. 



* Fourteenth Report on the State Cabinet of Natural History, p. 91, 1861. Published under the 

 name of C. ventricosa^ by mistake. 



