GEOMYIDJ5— GEOMYS MEXICANUS (517 



but neither in size nor color, it agrees with G. mexicanus; in both these 

 species, the single groove is central, bisecting the surface, so that, viewed 

 from the front, there appear to be four incisors. This separates it from G. 

 bursarius, with which it agrees in size, averaging about the same as G. bur- 

 sarius, though no specimens before me are as large as the largest of the latter. 

 Length, full grown, about 8 inches, rather less than more. Tail, 2£ to 3 

 inches. A notable peculiarity of form, in comparison with G. bursarius, lies 

 in the relative proportions of the fore and hind feet, which are much as in 

 GG. mexicanus and hispidus ; the palm, claws included, being shorter, or no 

 longer, than the sole and claws; the latter measuring about 1 £ inches, the 

 former only about 1^ inches. External ears obsolete. Hairiness of tail and 

 hind feet much as in average G. bursarius or G. mexicanus — they are thinly 

 clothed indeed, but more hairy than in G. luza or G. hispidus. 



Coloration dull, pale chestnut, or almost fawn-color, shaded with the 

 plumbeous basal portions of the fur. This tawny or fulvous tone is highly 

 characteristic in comparison with the deeper and warmer chocolate or mahog- 

 any or muddy-brown of G. bursarius and G. mexicanus. On the under parts, 

 though the plumbeous basal portion of the fur shows considerably, the general 

 tint is whitish — quite white in comparison with the muddy-gray of the same 

 parts of G. bursarius. • AVhiskers mostly colorless, or fine and numerous, the 

 longest about equaling the head. Claws pale horn-color; palms and soles 

 variously discolored. Incisors orange. 



Notwithstanding the difference in size and color, the affinities of this 

 species are decidedly with G. mexicanus rather than with G. bursarius. 



GEOMYS MEXICANUS, (Licht.) Rich. 

 The Tucan, or Mexican Pocket Gopher. 



Asvomys mexicanus, LicrtT.,»Abhand. K. Acad. Wiss. Berl. 1827, 113.— Brants, Muizen, 1827, 27.— Wagn., 



Suppl. Sehreb. iii, 1843, 384 ; iv, pi. 206 A.— Charlesw., P. Z. S. ix, 1841, GO (habits).— 



Schinz, Synop. ii, 1845, 133. 

 Saccophorus mexicanus, Fisch., Syuop. 1829, 305.— Eyd. & Gekv., '• Gncrin's Mag. vi, 1836, 23, pi. 21, f. 5, 



6; Voy. Favorite, v, 1839, 23, pi. 8, f. 5, 6".— Gray, List Mamm. Br. Mus. 1843, 150.— Gerr. 



Cat. Bones Br. Mus. 18(i2, 223. 

 Gcomys mexicanus, Rich., Sixth Ann. Hep. Brit. Assoc. Adv. Sci. for 1836, 1837, 150.— LeC, Proc. Acad. 



Nat. Sci. Phila. 1852, 160.— Baird, M. N. A. 1857, 387.— Coues, Proc. Phila. Acad. 1875, 133 ; 



Powell's Rep. Colorado R. 1875, 236 (monograph). 

 Pseudostoma (Geomys) mexicana, Aud. &. Bach., Q. N. A. iii, 1854, 309. 

 Gcomys (Saccophorus) mexicanus, GlEB., Siiug. 1855, 529. 

 Tucan of Hernandez. — Tuca or Tuza, Mexican. — Tugan apud Gerr., I. c. 

 Mcxicanisclie Taschenmaus, German. 



Diagnosis. — Superior incisors bisected by a single median furrow (as in 



