Plate XIV. 



Orthoceras timidum. 



Cyrtoceras corhulatum. 



Cyrtoceras MurcUisoni. 



Oyroceras alatum. 



Nautilus planotergatus. 



Lituites lituus. 



Bactrites (protoconch), 



Mimoceras compressum. 



Tropites phoehus. 



Lytoceras Liehigi. 



Crioceras Emerici. 



Turrilites catenatus. 



Baculites compressus. 



Macroscaphites Ivanii. 

 All figures are from J. P. Smith, Evolution of Fossil Cephalopoda, 

 Chapter IX, in D. S. Jordan's Footnotes to Evolution, 1898. They illus- 

 trate various stages in the evolution of Cephalopoda mentioned in the 

 text. 



