MAMMALS OF THE MEXICAN BOUNDARY. 477 



Type-locality. — ^Vicinity of Fort Lowell, Arizona. (Type in the col- 

 lection of the California Academy of Sciences.) 



Geographical range. — Elevated Central Tract (Dog Spring to So- 

 noyta, Monuments Nos. 55 to 167, on the Mexican Boundary), north 

 to the Colorado Plateau, south into Sonora and Chihuahua, Mexico. 



Description. — A large, dark form separating the smaller pallid forms 

 of the eastern and western deserts. Length, 330 mm. ; tail vertebrae, 

 155; hind foot, 34; ear from crown, 25. Skull, 45 by 23. Above 

 grayish yellow-brown, thickly lined with black; sides yellowish clay- 

 color; head grayish, washed with ochraceous on cheeks; feet and 

 under surfaces white; ears scantily coated with drab-colored hairs; 

 tail grayish black above, white below; orbital region dusky grayish; 

 whiskers long, black or colorless. 



Cranial characters. — Skull relatively broader than in Neotoma inter- 

 media and N. i. gilva. The wings of the sphenoid are further back 

 than in the true intermedia. 



Remarlcs. — This race is distinguished from the desert form angus- 

 ticeps on the east by the absence of pallor; from the dark Pacific coast 

 species intermedia it differs in being nlore yellowish brown, lacking the 

 olivaceous-gray tone of the latter. 



Habits and local distribution. — Neotoma albigula is the common 

 wood-rat of the Austral and lower Transition zones, from the Colo- 

 rado River to western Texas. East of the San Luis and Animas 

 mountains it grades into the form of the Eastern Desert Tract which 

 Dr. C. H. Merriam has distinguished as the subspecies angusticeps. 

 The typical form lives in various situations, but is usually found in 

 houses or mounds of rubbish that it heaps up by gathering together 

 sticks, stones, cow-dung, bones, bits of glass, plants, seed-pods, and 

 similar materials. The habit of accumulating is characteristic. In 

 George Hance's cabin. Bloody Basin, Arizona, where I spent the night 

 of April 19-20, 1888, these "trading" rats "packed" off some boxes 

 of pills in the night; but Mr. Hance awoke me and I recovered my 

 medicines after a chase. The rats were very bold in their forays 

 notwithstanding the presence of a house-cat. I trapped two white- 

 throated wood-rats in a closet of the quarters in which I lived, at 

 Fort Verde, Arizona, and had the satisfaction of recovering from 

 their nest a number of articles of household use that had been missed 

 by us from time to time, the loss of which had occasioned us some 

 inconvenience. Not until the young were half-grown was the nest 

 discovered. On another occasion a wood-rat gnawed a hole in a pan- 

 nier and destroyed a number of bird-skins. Hen's eggs were packed 

 off to the rats' nests; and pill and powder boxes were frequently 

 abstracted from the houses of my patients by this meddlesome and 

 pilfering rat. Large quantities — the whole annual supply — of candles 

 and soap (in cakes) were carried upstairs from the storeroom to 



