SECOND SERIES: PULMONATA 



MANUAL 



OF 



CONCHOLOGY 



VOL. XXVI 



PUPILLID^: 



(VERTIGININ.E, PUPILLIN.E) 



BY 

 HENRY A. PILSBRY, Sc.D. 



PHILADELPHIA : 

 PUBLISHED BY THE CONCHOLOGICAL DEPARTMENT 



ACADEMY OP NATURAL SCIENCES OP PHILADELPHIA 

 I920-I92I 



