PLATE 4. 



Fig. 1. — Banks inhabited by muskrats (Fiber z. spatulatus) at Portage 

 Cove, Revillagigedo Island; July 3, 1909. The burrows were excavated 

 in the walls of the gulches, the entrances being covered at high tide. 

 A pile of cut food is at the mouth of one of the burrows shown. 



Mg. 2. — Hoary Marmot (Marmota caligata) at entrance to burrow; 

 Port Snettisham, August 25, 1909. 



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