526 THE AMERICAN NATURALIST. [Vol. XXXV II. 



not of monophyletic origin. An examination of Conrad's type 

 from Vicksburg, Miss, in the collection of the Academy of Nat- 

 ural Sciences at Philadelphia shows it to have a protoconch of the 

 Levifusus type. This consists of about two and one-half volu- 

 tions ; the apical whorl is minute, and the succeeding ones 

 enlarge gradually. An angulation is formed by two spirals, above 

 which the shoulder becomes gently concave. The upper spiral 

 becomes stronger and alone forms the echinations in the later 

 whorls. Riblets appear early after the shell has become angu- 

 latedand these are soon reduced to mere tubercles. After two 

 whorls the latter become strong enough to be called spines. 



In the Lower Miocene of the Chipola River, Florida, occurs a 

 type with true Fulgur protoconch, which has been referred to 

 F. spiniger. This, together with the species referred by Dall to 

 /'. nodu latum, appear to be lateral branches from the main stem 

 which led to the modern types. Conrad's .V nodulatus has the 

 aspect of another extreme type of the Levifusus series, though 

 it may turn out to be a true Fulgur. 



At this time, as Dall has well said, the sutural canal was not 

 a well fixed character, having but just made its appearance. It 



