480 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



mexicana hullata. It was niiinerous on the upper course of the canyon 

 of Cajon Bonito Creek, near the })oundaries of the Mexican States of 

 Chihuahua and Sonora, and was also abundant in the San Bernardino 

 Valley, wSonora. At Niggerhead Mountain, south of Monument No. 

 82, its nests were particularly numerous. In the Mule Mountains, 

 Arizona, it was likewise abundant. On August 6, 1893, I took a 

 specimen at the altitude of 6,650 feet on San Jose Mountain, Sonora, 

 and subsequently one was entrapped among the stones composing the 

 monument at the summit. '^ It was abundant "in the Huachuca Moun- 

 tains, except near the summit, where it was replaced by Neotoma 

 mexicana hullata. It occurs throughout the San Pedro and Santa 

 Cruz valleys. Wlien collecting in the Patagonia Mountains, Sonora, 

 Mr. Holzner noted that " this wood-rat lives in rocks; builds no house;" 

 also that the specimens collected there by him had the iris very dark 

 brown and had two pairs of mamm* (inguinal). We took several 

 specimens in traps set in crevices of rocks at the sides of a sandy 

 arroyo on the Sonora side of the International Boundary near La Osa, 

 Arizona, December 8 to 28, 1893; but the species was uncommon 

 there. It was more abundant at Warsaw, Pima County, Arizona, in 

 November and December, 1893. It was common at Pozo de Luis, 

 Sonora, in December, 1893, and January following. Its houses were 

 often made of joints of cactus; and rat houses were seen in the highest 

 places, oftenest in the center of a large patch of prickly-pear cactus. 

 Some were taken in traps with much difficulty, for they were very 

 shy. The species was not abundant in the Nariz Mountains; but in 

 the Sonoyta Valley, at Sonoyta, Santo Domingo, and Quito])aquita 

 it was not uncommon, nesting about cacti and in brush fences. On 

 February 9, 1894, when I rode from Monument No. 179 west 30 miles 

 to Tule Wells, I saw piles of cactus joints accumulated by wood-rats at 

 a few places, but all were old and uninhabited. A few were found at 

 Tule Wells and at Tinajas Altas, n Arizona. In the Gila River bot- 

 tom, in the vicinity of Adonde Siding, Arizona, we found it common, 

 especially under the low, spreading mesquites and in piles of driftage 

 beside the Gila River. The examples entrapped were darker than 

 those taken at Tule Wells and Tinajas Altas, away from shade and 

 water. It was not noted west of G la City. 



a-Neotoma mexicana huilata Merriara was not found on San Jose Mountain. 



