EXPLANATlOxVS OF PLATE 17 (8). 

 Oncoceras (C^rtoceras ?) oRCAs. page 350 (46). 



Figs. 1, 2. Dorsal and lateral views of a large specimen. The figures are reduced to 

 two-thirds the natural size. 



CyrtocEras dardantjm. page 849 (45). 



Fig. 3. Lateral view of a specimen which preserves a part of the outer chamber and a 



small portion of the shell . 

 *' 4. Lateral view of an individual where the septa are not curved upward on the 



dorsal margin. 

 " 5. Transverse section of the specimen fig. 4. 



Cyrtoceras HBRCiTLES. page 358. 



(Cyrtoceras AMPLiooRNE, page 358.) 



Lituites hercules, Winchbll and Marc"? , Memoirs of the Boston Society of Natural 



History, Vol. 1, page 102, plate iii, fig. 9. 



Having had an opportunity of examining the original specimen of this species in the 

 collection of Prof. Marcy, I find that it is not a LiTtiTES, but possesses all the essential 

 features of the species described and figured by me (page 358, plate 17 (8) ) as 

 Cyrtoceras amplicorne. I therefore adopt the specific name of W. & M. 



Fig. 6. Lateral view of a large specimen which preserves a portion of the outer cham- 

 ber, and also some of the surface striae near the lower end. 

 " 7. Transverse section, showing the form of the shell. This and the preceding figure 

 are reduced one-third in siae. 



