20 



NORTH AMERICAN FAUNA. 



[No. 40. 



before the hair of the tail has renewed. At higher altitudes the 

 pelage is not completely renewed until the middle of July. When 

 the summer pelage is acquired this late the animals have molted 

 again and renewed into full fall pelage by the first of October, while 

 specimens from the lower levels, which acquired the summer pelage 

 much earlier, are sometimes as late as November in attaining the 

 same condition. 



Slcull and teeth. — The skull of C. I. arizonensis differs from that 

 of 0. 1, ludovicianus in the very broad surface of the superior maxillary 

 arm of the zygoma, bordering the ascending branch of the premaxilla 

 and the frontal bone, which in the typical examples is nearly twice as 

 wide as in 6^. Z. ludovicianus, less sharply emarginate anteriorly, and 

 rather more convex on the outer surface along the jugal. As a 

 result the maxillary arm of the zygoma appears to leave the rostrum 

 at a much less sharp angle than in the northern form. The audital 

 buUse average considerably larger than in typical ludovicianus. 

 Teeth essentially as in the northern race. 



Measurements. — ^Averages of 19 adult males from southeastern 

 Arizona: Total length, 388 (350-412); tail vertebrae, 89 (78-100); 

 hind foot, 62 (57-65). Slull: Condylobasal length, 60 (56.6-64); 

 zygomatic breadth, 44 (41-47.2); mastoid breadth, 27.3 (26.1-29.5); 

 length of nasals, 24 (22.3-25.4); length of mandible, 45.2 (42.8- 

 47.2); maxillary tooth row, alveoli, 16.2 (15.5-17). Females average 

 slightly smaller. For detailed measurements of specimens, see 

 page 35. 



Weight. — Three male specimens from Altuda, Texas, July 30, have 

 the following weights recorded in collector's field catalogue: 2 lbs. 

 2 oz., 2 lbs. 6 oz., and 2 lbs. 8 oz. 



Type specimens. — There are two co types, in the American Museum 

 of Natural History, New York: Skin (No. 2509, 9 ad.), from Point 

 of Mountain, near Willcox, Arizona, April 9, 1885; and skin and 

 skull (No. Trffj ^ ad., teeth considerably worn), from Dragoon 

 Summit, Arizona, May 3, 1885; both collected by Dr. Edgar A. 

 Mearns. Dr. Mearns later ^ restricted the type locality to Point of 

 Mountain, and listed No. ^^W" as the type specimen. Two female 

 specimens collected on the same date bear this skin number of the 

 American Museum. One has a skull numbered 12162, but the other, 

 without a skull number, bears a red type label, like No. 2185 from 

 Dragoon Summit. 



Remarks. — This is a slightly characterized form, barely recogniza- 

 ble except for average skull characters. Remarkable as it may seem, 

 there are specimens from near the type region which can be matched 

 in every particular with examples of typical ludovicianus from Mon- 

 tana. Nevertheless, as mentioned under the preceding form, about 



1 Mearns, E. A., Bull. 56, U. S. Nat. Mus., p. 339, 1907. 



