i:i: \\' III VI \. 





pic-ell! acrc|>lcd. Tin- l'i >l l ' \\ I II" -\ll"|>-i- will cxliil.il 



\ ;i rial ion^ in 1 lie '.M-iu-ra. 



AMMOM in. i, 



I'olCM OF >lli.l.I.. 



NAUTILI i> i.. 



With 



llli<lul:i I in- 

 Sllln 



Strai'di 



. . Orthoccra- . . . I lac' 



Sutures Sutures 



t hi- base. <>r lil 



Ilaciilina. 



Bacnlites, 

 Rhsbd< 



Toxooeras. 



Gomphooeras. 



Kent or cur\c<l Cyrtoccias. . . . 



Phragmoceraa 



idal s)irc and ( Ascocera^ 



tree whorls I < 



Finally straight 



Hook-shaped or bent 



upon it self more than 



. whorls free j Ilainito. 



Ibid. Straight portions 



in contact Ttychoccras. 



Litnite- . . 



( 



\ncylocei a>. 



1111'MlltlVI 



Involute, spiral Nautilus Goniatides. 



Nothoceras. 



Involute ; last cham- 

 ber detached, hook- 



Ceratites. Ammonites. 



Clydonites. 



ORDBB II. TETRABRANCHIATA. 



I. N \ i 1 1 1,1 ij;. Sc|)i.-i simply curved, concave on thr 



face, -uiiiro -iii)]dc. or iiii(lul:itr of lobcd ; mouth iiinpli' ; 

 u|u-iiini- iu-:irlv ccntr;)!. Slu-ll luit Little sculptured, or 

 smooth. 



Six li\ in-- an.l alxmt futi I'.^^il gpecieH. 



l-'ainily _'. A MMONITI D.I . Si-|.i:i con\r\ in ilioir iin-liaii -<- 

 lion. Milnn-s coni|)lo\. Inln-d. ramilinl or lrnl iciilat rl ; scptal 

 1ulr cylindrical and :il\v:iy- <lirrctcd t'(.rward<; --ipliiiiiclr rylin- 



