UNITED STATES NATIONAL MUSEUM 
Bulletin 112 
SMITHSONIAN INSTITUTION 
SUMMARY OF THE MARINE SHELLBEARING MOL- 
LUSKS OF THE NORTHWEST COAST OF AMERICA, 
FROM SAN DIEGO, CALIFORNIA, TO THE POLAR SEA, 
MOSTLY CONTAINED IN THE COLLECTION OF 
THE UNITED STATES NATIONAL MUSEUM, 
WITH ILLUSTRATIONS OF HITHERTO 
UNFIGURED SPECIES 
BY 
WILLIAM HEALEY DALE 
Honorary Curator of Mollusks, United States National Museum 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
