424 BULLETIN 56, UNITED STATES NATIONAL MUSEUM, 



Texas, collected by the indefatigable Attwater. In describing it, I 

 can not do better than transcribe Doctor Allen's original description: 



Above tawny brown, darker and much mixed with blackish along the median dorsal area, 

 more golden on the sides, the lower edge of the dorsal area forming a strongly-defined golden 

 lateral line. Below pure white, the base of the fur plumbeous. Fore feet white to slightly 

 above the wrists; hind feet white nearly to the tarsal joint, soles naked nearly to the heels. 

 Ears very large, nearly naked, dusky, faintly edged with whitish. Tail sharply bicolor, dusky 

 above, grayish below, moderately well haired (the annulations showing through more or 

 less toward the base), and generally well tufted at the end. 



Measurements. — Average of 10 adult specimens, measiu'ed in flesh: Total length, lOfi (LS?- 

 210) mm.; tail vertebra-, 100 (9(j-110): hind foot, 21 (20-23); ear from notch (measured 

 from the skins), 16 (1.5-17). Th(> type, a breeding female, is rather above the average of the 

 .series, measuring as follows: Total length, 216; tail vertebra^ 110; hind foot, 28; ear, 17. 



Skull (of type), total length, 2S; basilar length, 26; greatest cranial breadth, 14; least 

 interorbital breadth, 5; length of nasals, 9.5. 



This species is based on a series of 14 specimens collected on l^urtle Creek, Kerr County, 

 Texas, May 24, 1894, and March 9-13, 189.5, and on 3 from San Geronimo Creek, Medina, 

 County, Texas, April 23, 189.5. Several are in the nearly uniform dark-gray pelage of the 

 yoiuig, others are more advanced, but still immature, 'while about one-half are "young" 

 adults, only a few being "old" adults. One only (the type) has a very small spot of l)right 

 fulvous on the breast. 



Peromysciis nttiraferi finds its nearest adines in Peromyscus 7VHiei/i and P. eremicufi, but 

 seems to be clearly did'erent from either. 



.This species is named for the collector, Mr. H. P. Attwater. (Bull. Am. Mus. Nat. His. 

 VII, p. 330.) 



Description of young. — A young specimen in gray pelage, taken 

 December 'M, 1S92, at Fort Clark, Kinney County, Texas, by the 

 author, and identified as this mouse by Doctor Allen, is mouse-gray 

 above, and white below. It is beginning to receive the longer coat, 

 appearing first on the chest. An older specimen, taken at the same 

 place, January 12, 1S9.3, is more advanced, having the adult coating 

 on the ventral surface and a colored line on tlie side. One taken two 

 days earlier has the colored coat throughout, l^ut is duller than adults, 

 the u})])er surface being hair-brosvn. The feet of the three Fort Clark 

 sjiecimens are as naked below as those of Peroniyscus hoylii penicilla- 

 tus; and, like that subspecies, and also P. eremicus, the nasals are 

 truncate, ending in front of the premaxillaries. 



Ilahits and local distribution. — The Attwater brush mouse finds its 

 home in high ground, in brushwood, Avhere there are crevices in the 

 rocks. It is seldom found in \\ oods near the streams. 



