Frdc.CalAcad.Sci.3^ Ser.Gedl.VdlI. 



[SmithIPiate Xr\/III. 



o 



F17.SMlTH.nEL 



Fid's. 1-5. Placenticeras pacificum, 

 fig.b.placenticeras califdhnicum, 



PHDTQ.-UTH.HHlXrDN 8c REr, S F. 



Fig. 7 FIAPHD RITES VETULDNIUS. 



Fid. a. Placenticeras duadalduf^ 



