SECOND SERIES: PULMONATA. 



MANUAL 



CONCHOLOGY 



STRUCTURE AND SYSTEMATIC. 



WITH ILLUSTKATIONS OF THE SPECIES. 



FOUNDED BY 



GEORGE W, TRYON, JR. 



CONTINUED BY 



HENRY A. PILSBHY, Sc. D., 



SPECIAL CURATOR OF THE DEPARTMENT or MOLLUSCA, ACADKMY OF 

 NATURAL SCIENCES OF PHILADELPHIA. 



VOL XVII. 



AFRICAN ACHATINID.E. 



PHILADELPHIA: 

 Published by the Conehological Department, 



ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA. 

 1904-1905. 



