KEY TO LAND MAMMALS OF NORTHEASTERN NORTH AMERICA IO7 



Microtus pennsylvanicus fontigenus (Bangs) Northern field mouse 



1896 Microtus fontigenus Bangs, Proc. biolog. soc. Washington. 9 Mar. 



1896.p.48. (Lake Edward, Quebec) 



1897 Microtus pennsylvanicus fontigenus Miller, Proc. Boston 



soc. nat. hist. 30 Ap. 1897. 28 : 14. 

 1900 Microtus pennsylvanicus fontigenus Bailey, North Ameri- 

 can fauna. 6 June 1900. no. 17, p. 21. 



Upper parts clear sepia brown without tawny tinge ; under parts light gray ; 

 skull narrow. Total length., 140 (5^) ; tail vertebrae, 40 (ib) ; bind foot, 20 (f ). 

 (fontigenus; Lat., spring-born) 



The northern field mouse inhabits fields, barrens and dry woods in the 

 Hudsonian zone of eastern North America from Quebec to the north 

 shore of Lake Superior. 



Microtus pennsylvanicus acadicus Bangs Acadian field mouse 



1897 Microtus pennsylvanicus acadicus Bangs, American nat- 



uralist. Mar. 1897. 30:239. (Digby, Nova Scotia) 

 1900 Microtus pennsylvanicus acadicus Bailey, North American 

 fauna. 6 June 1900. no. 17, p. 19. 



Upper parts varying from bister shaded with rnsset to almost clear russet ; 

 under parts dark gray; skull slender. Total length, 167 (Gts) ; tail vertebrae, 

 45 (If); hind foot, 20 (f). (acadicus; N. Lat., Acadian) 



The Acadian meadow mouse is confined to the fields, fresh water 

 marshes and forest glades of Nova Scotia. 



Microtus nesophilus Bailey Gull island mouse 



1898 Microtus insularis Bailey, Proc. biolog. soc. Washington. 12: 86. 



(Great Gull island. Long Island, N. Y.) not Lemmus insularis 

 Nilsson. 



1899 Microtus nesophilus Bailey, Science, n. s. 2 Dec. 1898, 8 : 782. 



1900 Microtus nesophilus Bailey, North American fauna. 6 June 1900. 



no. 17, p. 26. 



Upper parts dark brown, slightly darker than in average specimens of M. 

 pennsylvanicus; under parts dusky, washed with cinnamon; teeth as in 

 M. pennsylvanicus; skull with sliort droad hraincase. Tail vertebrae, 

 29 (H) ; hind foot, 20 (f). (nesophilus; Gk., island lover) 



The Gull island mouse is confined to Great Gull island and Little Gul 

 island, off the eastern extremity of Long Island, New York, The species 

 is probably extinct. 



