No. 415.] POSITION OF THE ALCA. 
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un 
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EXPLANATION OF THE PLATE. 
‘Lalas, aay wl U.S 
Skeleton of the Great Auk (Plautus impennis). Reduced. Coll. U.S. 
E xc e è a D es 
National Museum, No. 18,117. This skeleton is made up of the bones of 
numerous individuals. 
