PLATE XII. 



MACROCHEILUB ? (CalLONEMA?) PRIMJEVU8. 

 I'niru St. 

 Vig. 1. Lateral view of an iui|)ei-fect cast. 

 F1({». 2, 3. Two views of a larg«r iiulividiiul, whicli is obliiiuely cnisheil. 



Macrocheilis Heue. 



I'uge S-l. 

 FSgS. 4, 5. Two views of a lar^ individual (natural size). From the Hamilton g-rouji, Pavilion, Genesee 



county, N. Y. 

 Figs. 6, 7. The opiHwite sides of the typical 8])ecimen enlarged to three diametei-s. From the Goniatite 



limestone of the Marcellus shale, near Manlius, N. Y. ^ 



MaCROCHEILUS HAMILTONI.a!. 

 Page 33. 

 Figs. 8, 9. VJewB of the opposite sides of the ty^iical specimen. 



Figs. 10, 11. The opiHWite sides of an internal cjist. From the Hamilton group, Cumberland, Md. 

 Figs. 13-14. A 8|)eciinen which has been denuded of the spire and flattened vertically so as to change entirely 

 the character of the shell. 



Macrochkilus (Holopea) macrostomcs. 



Page 33. 



Figs. 15, 16. The opposite sides of the typical specimen, showing the foi-m of the shell and surface charac- 

 ters. Hamilton group at Pratts Falls, Onondaga county, N. Y. 



Fig. 17. An infernal cast, referred to this sjiecies. From the same locality. 



Rg. 18. A compresseti specimen, I'efei'red to this species ; the spire is more elevated than usual, but the 

 other characters ai-e similar. Hamilton group, Madison county, N. Y. 



Callonema Lichas. 



Page Si. 

 Fig. 19. A specimen in which the sui^ace is partially preserved. 

 Figs. 20, 21. Views of the opjx>site sides of a larger specimen preserving the substance of the shell on some 



parts. Fi-om the Upper Helderberg limesione near Clai-ence Hollow, N. Y. 

 Fig. 22. An internal cast from near Columbus, Ohio. 



Cyclonema Doris. 



Page 34. 

 Fig. 23. A specimen of this species preserving the usual form. From the Schohai-ie grit, Schoharie, N. Y. 



Plecrotomaria ? gp. ? 



Fig. 24. A Bi)ecimen almost entii-ely denuded of the shell, but retaining impressions of the revolving band 

 on the Ixxly-volution. From the Upper Helderberg limestone, Clai-euce Hollow, N. Y. This 

 form may be a cast of Pleurotomaria Ityn. 



Plkuroto-maria capillaria? 



Piige 77. ; 

 Fig. 25. Enlargement of a specimen which is referreil with doubt to this species. From the Upper Helder- 

 berg limestone, Williamsville, N. Y. 



