SECOND SERIES: PULMONATA. 



MANUAL 



CONCHOLOGY 



STRUCTURAL SND SYSTEMATIC. 



WITH ILLUSTRATIONS OF THE SPECIES. 



POUNDED BY 



GEORGE W, TRYON, JR. 



CONTINUED BY 



. -V 



HENRY A. PILSBRY, Sc.D., 



SPECIAL CURATOR OF THE DEPARTMENT OF MOLLUSCA, ACADEMY or 

 NATURAL SCIENCES OF PHILADELPHIA. 



VOL. XVIII. 

 ACHATINID^E : STENOGYRIN^E AND CCELIAXIN^. 



PHILADELPHIA : 

 Published by the Conchological Department, 



ACADEMY OP NATURAL SCIENCES OF PHILADELPHIA. 



1906. 



