, Off OOCB 1 -II 



PILOCERAS, - 



Shell hro;id. coiiic;d. ->iihc\ lind ric:d or (M>nipreflHed, Slightly 

 curved. Tin- siphiincle :iml M-pl:i re| .re-en I ed hy :i ^cri' 

 'ouie;d sept;i. coiic.MVe to :i central poillt. 



l-'"--il. t hree ^pecio. L. Siliiri:m. ('tannin: S 



Pn.o, KI; \>. LI,..-, I section. H. HT. ii-. 186, 



J.-nu- CYRTOCERAS 



Shell curved ; sipliiinclc >ni;dl. siiln-riit r:il. 



Fossil, eighty -four s|>eeies. L. Sihii-i;in to C:irl. N.nint >'. 

 .\nn-rifii : Enrobe. 



Seem- !o ditf'ei' hut little from (trthorrriia. 

 < . L01 n< 08TAT1 M. S;iudh. PI. ( .T. li'. tsT. 



Subgenera : 

 Oncoceras, Hall. 



Anterior h;dt' of the shell intl.Mtcd. Mpcrtui'c inorr or (ese 

 ^t r:ino-ul.Mtcd. 'I'his in;i\ possihlv Plirtnjinm-i'rfin. Hnl. 



Silurinn. j^et^ York. Three speeies. 

 O. OON8TRTOT1 M. Hall. PI. ( .7. I'm". 488. 



Cyrtocerina, Billings. 



Shell short and thick, with a l:irv siphuucle. place<l dors.-dly. 

 Two ^pecies. Silurian. Canmlu. 



Streptoceras, Billings. 



Shell like Oncoceras. hut the a|erture trilohrd. 

 Two specie^. Middle Silurian. (!iinm/<i. 



QU GOMPHOCERAS, .1. S.nvl.. 

 Shell I'lisitorin or hot t le-shaped. straight, BWolleo anteriorly; 



aperture contracted in the middle: siphuncle subcentral ; >epta 



>illlple. co||e;i\ C. 



HID pecie->. I,. Silurian to ( 'ark /.'///o/;.-.- A". [fltertCO* 

 <;. I'MUFoHMK. I'l. '.>T. fiir. 4s-.. Silurian. Kinjlinnl. 



(i. P.nllKMU'l M. r.MIT. PI. '.7. fl-. P.H>. A|>ertlire. 



