THE 



NAUTILUS 



A QUARTERLY JOURNAL 

 DEVOTED TO THE INTERESTS 

 OF CONCHOLOGISTS 



VOL. XXXI 

 JULY, 1917, to APRIL, 1918 



if 79 



EDITORS AND PUBLISHERS 



HENRY A. PILSBRY 



Curator of the Department of Mollusca, Academy ot Natural Sciences 

 Philadelphia 



CHARLES W. JOHNSON 



Curator of the Boston Society of Natural History 

 Boston 



