Brewer's Beach Mous* 



Varieties of the Meadow Mouse 



/. Ivkauoiv Mouse. Microfus penusylvaniLiis (Ord.) Description 



and r.inge as above. 

 2. Black Meadoi: Mouse. M. pennsy/vatitctis nigrans Rhoads. 

 Mucii darker, black hairs predominating, 

 Rancie. Coast of V^irginia and Nortii Carolina. 

 jj. Acaclian MeiiJoiv Mouse. M. pennsylvanicus acadicus Bangs. 

 Brighter and more strongly russet than M. pennsylvavicus. 

 Range. Nova Scotia. 



4. Labrador Meadow Mouse. M. pennsylvanicus enixus (Bangs). 



Similar to the meadow mouse in color but with peculiar skull, 

 and light projecting front teeth. 

 Range. Labrador. 



5. Ungava Meadow Mouse. M. pennsylvanicus ungava Bailey. 



Smaller than the meadow mouse with very broad peculiar 

 skull. 

 Range. Ungava, Northern Labrador. 



6. Hudsonian Meadow Mouse. M. pennsylvanicus foniigenui 



(Bangs). Smaller than the meadow mouse with no tawny 

 tints, skull narrower. 

 Range. Quebec and Ontario, in deep forests. 



7. Gull Island Mouse. M. nesophilus Bailey. Very similar externally 



to the meadow mouse, but with a peculiar skull. 

 Range. Little Gull Island N. Y. 



Brewer's Beach Mouse 



Microtiis breweri (Baird) 



Length. 7.80 inches. 



Description. Larger than the meadow mouse with rather coarse fur, 



pale grayish yellow-brown above, ashy white below, with a 



tint of buflf. 

 Range. Muskeget Island, Mass. Formerly also on Adams and South 



Point Island two small islets south of Muskeget. 



This curious pallid mouse, originally derived from the same stock 

 as the dark meadow mouse of the mainland, is a striking illustration 

 of the effect of environment in moulding species. Not only has it 

 changed materially in color, but its habits and mode of life have also 

 undergone modification. The sandy soil of the island upon which 

 it lives precludes the possibility of burrows, except perhaps in winter, 

 and the mice pass the greater part of the year exposed to the full force 



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