Bulletin of the Museum of Comparative Zoology 

 AT HARVARD COLLEGE. 



Vol. XXII. No. 4. 



A FOURTH SUPPLEMENT TO THE FIFTH VOLUME OF THE TER- 

 RESTRIAL AIR-BREATHING MOLLUSKS OF THE UNITED 

 STATES AND ADJACENT TERRITORIES. 



By W. G. Binnet. 



With Four Plates. 



CAMBRIDGE, U.S.A.: 



PRINTED FOR THE MUSEUM. 



January, 1892. 



