26 



ITOETH AMEEICAN FAUNA. 



[No. 37. 



to clove brown or black; underparts varying from burnt sienna to 

 Sanford's brown, more or less mixed with tawny, ochraceous-buff, 

 and black (general tone of under parts usually reddish but sometimes 

 mixed brown and bu^f with little red) ; tail Vandyke brown to clove 

 brown or black. Variation: Specimen from Essex County, N. Y. : Very 

 dark chestnut-brown above (the underfur pinkish cinnamon), moder- 

 ately grizzled on fore back with buffy white; hinder back solid brown. 



SJcull. — Similar to that of monax, but decidedly smaller and 

 relatively broader across zygomata; much larger than that of cana- 

 densis; slightly larger than that of ignava, but narrower across 

 orbits and with narrower nasals. 



Measurements. — Adult male: ^ Total length, 520-582 (average, 

 548); tail vertebrae, 135-155 (143); hind foot, 81-85 (83). Adult 

 female: 2 Total length, 545-608 (571); tail vertebrae, 145-170 (156); 

 hind foot, 83-89 (85). Slcull: Adult male:^ Condylo-basal length, 

 81.3-94.4 (88.6); palatal length, 50.7-54.5 (51.8); postpalatal 

 length, 32-36.4 (33.5); length of nasals, 33.9-39.8 (36.8); zygo- 

 matic breadth, 53.4-64.7 (60.2); breadth across mastoids, 40.3-46 

 (43.2); least interorbital breadth, 21.7-25.4 (23.8); breadth 

 of rostrum, 18-21.2 (19.4); maxillary tooth row, 18.7-21.8 (20.1). 

 Adult female:^ Condylo-basal length, 84-88.9 (85.8); palatal 

 length, 49.1-52.4 (50.6); postpalatal length, 31.5-31.8 (31.6); length of 

 nasals, 33.4-39.1 (35.6); zygomatic breadth, 57.5-62 (59.9); breadth 

 across mastoids, 40.6-43.8 (42.4) ; least interorbital breadth, 22.2-26.3 

 (23.6); breadth of rostrum, 18.2-20.4 (19); maxillary tooth row, 

 17.5-21 (19.7). 



Remarlcs.' — The woodchucks of the Northern States, from Minne- 

 sota to New Yorkj differ from typical monax of the Middle States 

 in having smaller skulls and darker colors, the underfur especially 

 being more strongly reddish. The race shows a strong tendency 

 toward melanism, particularly in New York and southern Ontario. 

 The New York series differs from the Minnesota series in somewhat 

 longer and relatively narrower skulls, being, therefore, more like 

 monax, but the differences between the two extremes are too slight 

 and inconstant to warrant recognition of another form. Specimens 

 from the Catskill Mountains are fairly typical of rufescens, but those 

 from the Hudson Valley and Lake George are clearly intermediate, 

 the skulls being almost typical of monax and the skins, of rufescens. 

 These show no approach to the New England form (preUorum). 

 Two skulls (without skins) from Easthampton, Mass., are fairly 

 typical of rufescens, indicating that this race probably occupies the 

 higher parts of western Massachusetts. A specimen from Lake of 

 Bays, Ontario (east side of Georgian Bay), considered intermediate 

 between rufescens and canadensis, is very deep red below — fully 



1 Five specimens from Elk River and Fort Snelling, Minn. s Eleven specimens from Minnesota. 



2 Five specimens from Fort Snelling, Minn. * Five specimens from Minnesota. 



