DESCRIPTIONS OF SIX XEW MAMMALS FROM NORTH 



AMERIOxV. 



By Edgar A. Mearns, M. D., 



Assistant Surgeou, United States Army. 



Among the collections of mammals lately made by the writer iu the 

 southwestern part of the Uuited States are se^'eral forms that appear 

 to be new to science. These are described in the present paper, together 

 with an apparently new species of wood rat, sent to me for determi- 

 nation by Doctor J. A. Allen, curator of mammals in the American 

 Museum of Natural Historj^ New York. 



. THOMOMYS FULVUS INTERMEDIUS, new subspecies. 

 INTERMEDIATE POCKET-GOPHER. 



Type. — No. f^ii^y, U.S.N.M, (Collection International Boundary Com- 

 mission). Adult male, from the aspen and spruce zone at the summit 

 of the Huachuca Mountains, Arizona; altitude, 0,000 feet. Collected 

 by Mr. F. X. Holzner, September G, 1893. Original number, 1013. 



Description of type. — Slightly smaller than Thomomys fulv us, equaling- 

 T. peregrinm. General color mars brown, with a broad dorsal area of 

 plumbeous black extending from nose to rump. Feet and tail soiled 

 white. When the pelage is worn, the plumbeous underfur shows through 

 between the tips of the hairs of the under surface. Length, 220 mm, ; 

 tail, 00; hind foot, 24. Skull, 31.5 by 22. 



Geographical range. — The Boreal Zone of the chain of mountains con- 

 necting the Colorado Plateau with the Plateau of Mexico. 



Reniarls. — This form is intermediate between Thomomys f ulvns {Wood- 

 house) and T. 2)crcgrinus, Merriam, though in some respects peculiar. 



DIPODOMYS MITCHELLI, new species. 

 TIBURON ISLAND KANGAROO RAT. 



Two specimens of a new kangaroo rat, closely related to DijJodomys 

 merriami simiolus, Rhoads, have recently been sent me by Mr. J. W. 

 Mitchell, who traj^ped them on Tiburou Island, in the Gulf of California, 

 Mexico. Mr. Mitchell has, for some time past, been engaged in making 



Proceedings U. S. National Museum, Vol. XIX— No. 1121. 



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