GEOMYID“Z—GEOMYS MEXICANUS 617 
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, 24 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 14 inches, the 
former only about 14 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. ¢uza 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. Whiskers 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. mezxicanus rather than with G. bursarius. 
GEOMYS MEXICANUS, (Licht.) Rich. 
The Tucan, or Mexican Pocket Gopher. 
Ascomys mexicanus, Licut., Abhand. K. Acad. Wiss. Berl. 1827, 113.—Brants, Muizen, 1827, 27.— WaGn., 
Suppl. Schreb. iii, 1843, 384;-iv, pl. 206 AW—CHartesw., P. Z. S. ix, 1841, 60 (habits).— 
Scn1nz, Synop. ii, 1845, 133. 
Saccophorus mexicanus, FIscu., Synop. 1829, 305.—Eyp. & GEry., “ Guérin’s Mag. vi, 1836, 23, pl. 21, f. 5, 
6; Voy. Favorite, v, 1839, 23, pl. 8, f. 5, 6”.—Gray, List Mamm. Br. Mus. 1843, 150.—GErR. 
Cat. Bones Br. Mus. 1862, 223. 
Geomys mexicanus, Rrcu., Sixth Ann. Rep. Brit. Assoc. Ady. Sci. for 1836, 1837, 150.—LEC.,.Proc. Acad. 
Nat. Sci. Phila. 1852, 160.—Barrp, M. N. A. 1857, 387.—Covrs, Proc. Phila. Acad. 1875, 133; 
Powell’s Rep. Colorado R. 1875, 236 (inonograph). 
Pseudosioma (Geomys) mexicana, AuD. & Bacu., Q. N. A. iii, 1854, 309. 
Geomys (Saccophorus) mexicanus, GIEB., Siiug. 1855, 529. 
Tucan of HERNANDEZ.—Tuca or Tuza, MEx1cAN.—Tugan apud GERR., L. ¢. 
Mexicanische Taschenmaus, GERMAN. 
Diacyosts—Superior incisors bisected by a single median furrow (as in 
