NATURAL SCIENCES OF PHILADELPHIA. 325 



ears, and longer limbs, and especially longer tail. It is darker in 

 color, the prevailing tone being a mouse-brown overcast with 

 tawny or fulvous. The animal from the interior is larger, and 

 noticeabby more stoutly built, with smaller ears, and shorter limbs, 

 and particularly shorter tail. It is lighter in color, the prevailing 

 tone being the peculiar tawny or fulvous of the genus, deepened 

 somewhat on a dorsal area with mouse-brown. 



These are simply observed matters of fact, not open to question. 

 Certain differences which actually exist, as well as the insensible 

 blending of these differences, may both be fairly signalized by the 

 following formulae of nomenclature and description, in which the 

 various names which have been proposed are relegated to their 

 proper place, covering diagnosis of typical (i.e. extreme) charac- 

 ters, and indication of the region in which such form more espe- 

 cially prevails : 



Dipodomys phillipsi, 1 Gray. 



Dipodomys phillippii, Gray, Kep. Brit. Assoc. 1841, 70; Ann. Mag. N. 



H. vii. 1841, 521. Real de Monte, Mex. (Type of genus.) Gray, 



Am. Journ. Sci. xlii. 1842, 335. Wagn., Suppl. Schreb. iii. 1843, 



295. -Le C, Proc. Acad. Nat. Sci. Phila. vi. 1853, 224. (Sacramento 



Valley, Cala.) Gieb., Saug. 1855, 600. (Compiled.) Baird, M. N. 



A. 1857, 442. (California, etc.) Coop, and Suckl., P. R. R. Rep." 



xii. 1859, Mamm. pp. 100, 127. 

 Dipodomys pMlippi, Schinz., Syn. Mamm. ii. 1845, 93. (Compiled from 



Gray.) 

 Dipodomys phillippsii, Aud. and Bach., Q. N. A. iii. 1853, 137, pi. 130. 



(From Gray's type.) 

 Dipodomys phillipsii, Gray, List. Mamm. Br. Mus. 1843, 120. Gerr., Cat. 



Bones Br. Mus. 1862, 173. Gray, Proc. Zool. Soc. 1868, 200. 

 Dipodomys phillippii, Baird, P. R. R. Rep. x., 1859, Williamson's Route, 



Mamm. p. 82. 

 Macrocolus halticus, Wagn., Abh. K. Baier. Akad. xxii. 1845, 319; Arch. 



f. Naturg. 1846, 172. Giebel, Saug. 1855, 599. (Compiled.) 

 Dipodomys agilis, Gamb., Proc. Acad. Nat. Sci. Phila. iv. 1848, 77. (Los 



Angeles.) Le C, Proc. Acad. Nat. Sci. Phila. vi. 1853, 224. A. 



and B., Q. N. A. iii. 1854, 339. (Compiled). Gieb., Saug. 1855, 



600. (Compiled.) Bd., Proc. Acad. Nat. Sci. Phila. 1855, 334 (San 



Diego) ; M. N. A. 1857, 414, pi. 9, f. 1. Gray, P. Z. S. 1868, 201. 

 Dipodomys heermanni, Le C, Proc. Acad. Nat. Sci. Phila. 1853, 224. 



(Sierra Nevada.) 



1 This name is found variously spelled by authors, as well as by Gray 

 himself; but if, as stated by Gray, the species was named after John Phil- 

 lips, the rendition here adopted appears to be most correct. 



