THE 



NAUTILUS 



A QUARTERLY JOURNAL 

 . DEVOTED TO THE INTERESTS 

 OF CONCHOLOGISTS 



VOL. XXXIV 

 JULY. 1920, to APRIL, 1921 



EDITORS AND PUBLISHERS 



HENRY A. PILSBRY 



Curator of the Department of Mollusca, Academy of Natural Sciences 



PHILADELPHIA 



CHARLES W. JOHNSON 



Curator of the Boston Society of Natural Hurtoiy 

 BOSTON 



