600 Bulletin American Museum of Natural History. [Vol. XIX, 



length of 162 (145-181, only 3 above 170) as against 173 for ftaccidus; 

 tail vertebrae, 72 (59-80, only 3 above 74) as against 79; hind foot, 

 22.4 as against 20.5. 



Represented by 64 specimens, collected as follows: Rosario, 6, Jan. 

 24 and 25; Rio de las Bocas, 4, Feb. 8 and 9; Villa Ocampo, 3, Feb. 

 14; La Boquilla, i, Feb. 16; San Gabriel, 5, Feb. 17-20; Rancho 

 Santuario, 3, Feb. 21-25; Rio Sestin, 42, April 914. Among the 

 April specimens are many young, one quarter to nearly full grown, 

 and the January-February specimens contain a few young adults, but 

 consist mostly of adults, showing that the young arejnot born till some 

 time in March or later. 



This subspecies seems to most resemble arizonce of the 

 texanus group, but adults are slightly paler and more fulvous, 

 and young in first coat, as well as young adults, are decidedly 

 paler and more ashy gray. The skulls present no distinctive 

 features, but the differences in size, and especially the longer 

 tail and shorter hind foot, seem noteworthy. 



Although a pallid form it differs very appreciably in colora- 

 tion, and also in size, from P. t. medius Mearns from the 

 desert coast belt of northern Lower California. 



ii. Peromyscus boylii pinalis (Miller}. 



Represented by 66 specimens, all adult, collected as follows: 

 Mount San Gabriel, 5, Jan. 28; La Boquilla, 6, Feb. 14-16; 

 San Gabriel, 12, Feb. 17-20; Rancho Santuario, 24, Feb. 27- 

 March 7; Matalotes, 7, March 23 and 24; La Cienega de las 

 Vacas, 7, March 2131 and April 6; Arroyo de Bucy, 3, May 

 23; without locality, 2, and several additional skulls. 



Ten adults from San Gabriel measure: Total length, 190 

 (181-209); head and body, 90.3 (86-98); tail vertebrae, 99.5 

 (95-114); hind foot (without claws), 19.4 (19-20.5); ear from 

 notch, 19 (17.5-20.5). 



These specimens do not differ appreciably from a large 

 series from the southern border of Arizona, either in size, pro- 

 portions, or coloration. 



12. Sigmodon minimus Mearns. 



Twenty-four specimens, as follows: Rosario, 9, Jan. 21-29; 

 Rio Sestin, n, April 6-16; Rancho Bailon, 4, May 4-10. 



