ONE DOLLAR 
EACH IS OFFERED for one copy of THE 
AMERICAN NATURALIST for December, 1888, 
and for December, 1891. 
LOCKBOX 2, WILLIAMSTOWN, MASS. 
MARINE BIOLOGICAL SUPPLY DEPARTMENT 
Preserved material of all types of animals, for class 
w 
or for the museum. For = e list 
oa all information, address 
GEO. M. GRAY, CURATOR - - Yo HOLL, MASS. 
DISSECTING MICROSCOPES 
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A new series of lenses 
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in use. The new Dissecting Stands are all nickeled 
metal with glass stage. 1@- Catalog free. 
Sample copy, JOURNAL OF APPLIED MICROSCOPY on request, 
BAUSCH & LOMB OPTICAL CO. 
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