MAMMALS OF THE MEXIOAW BOUNDARY. 449 



Description. — Externally this species may be readily distinguished 

 from the preceding (Sigmodon minimus) by its grayish-white under- 

 surface, the finer grizzle of its upper surface, its less blackish tail, and 

 considerably larger size. The skull of minimus may be immediately 

 recognized by the characters pointed out above. Specimens of Sig- 

 modon hispidus texianus, taken at Fort Clark, Kinney County, Texas, 

 near the upper Nueces River, may be regarded as typical of this 

 form. They are a little paler than those from Brownsville, near the 

 mouth of the Rio Grande. The upper surface is yellowish brown, 

 finely mixed with black and dull gi'ayish. The coloration is quite 

 uniform, though there is less black on the sides than above. Under- 

 surface grayish white, the long white overhair permitting the gray 

 imderfur to show between them. The underfur is plumbeous above, 

 much paler than in S. minimus. Tail brownish black on upper lon- 

 gitudinal third, dirty grayish elsewhere, duller above as the coat 

 fades. The feet are grayish white. Length, 250 mm.; tail, 100; ear 

 from crown, \2.^^■, hind foot, 32. Skull, .32 by 19 mm.« 



Remarks. — Dr. J. A. Allen ^ has clearly shown the validity of the 

 subspecific characters of the Texas cotton-rat, and has also shown 

 that it is the animal described as Arvicola texianxi by Audubon and 

 Bachman. 



SIGMODON HISPIDUS BERLANDIERI (Baird). 

 EASTERN DESERT COTTON-RAT, 



Sigmodon herlandieri Baird, Proc. Acad. Nat. Sci. Philadelphia, VII, 1855, p. 333; 



Mam. N. Am., 1857, p. 504 (part); Rep. U. S. Mex Bound. Surv., II, Pt. 2, 



Mam., p. 46 (part). 

 Sigmodon Mspidus paUidus Meaens, Proc. U. S. Nat. Mua., XX, 1898, p. 405 (advance 



sheet issued Mar. 5, 1897). — ^Milleb and Rehn, Proc. Bost. Soc. Nat. Hist., 



XXX, No. 1, Dec. 27, 1901, p. 90 (Syst. Results Study N. Am. Mam. to close of 



1900). 

 Sigmodon hispidus lerlandieri,_'BAii,EY, Proc. Biol. Soc. Washington, XV, p; 106, June 2, 



1902 (in part) (Synopsis of the North American Species of Sigmodon). — Miller 



and Rehn, Proc. Bost. Soc. Nat. Hist., XXXI, Aug. 27, 1903, p. 80 (Syst. Results 



Study N. Am. Mam. during the years 1901 and 1902). 

 [Sigmod(m hispidus] pailidus, Elliot, Field Col. Mus., Zool. Ser., II, 1901, p. 145 



(Synop. Mam. N. Am.). 

 [Sigmodon] hispidus herlandieri, Elliot, Field Col. Mus., Zool. Ser., IV, 1904, p. 227 



(Mam. Mid. Am.). 



Type-locality. — Left bank of the Rio Grande, opposite the initial 

 Monument (No 1), and about six miles above El Paso, Texas. (Type, 

 skin and skull. Cat. No. tWt> U. S. National Museum.) 



Geographical range. — Inhabits the edge of streams flowing through 

 the ancient lake basins of the upper Rio Grande, in the Eastern DeseTt 

 Tract. 



a See also p. 452. 6 Bull. Am. Mus, Nat. Hist., II, 1889, p. 175. 

 30639— No. 56—07 m 29 



