I'.lM MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



Geomys borealis, Rich., Eep. Brit. Assoc, for ls:;c, % i, 1837, 150, described on p. l.'.r. (" Saskatchewan.")— 

 Bachm., .Iiimiii. Acad. Nat. Soi. Pbila. L839, 103. (Origiually described from Richardson's 



type, "Col iii:i 1.'.," marked " Pseudosioma borealis, Rich.") DeKay, N. Y. l'n. 1842, 



92. (Compiled from Bacbman.) — Schlnz, Synop. Mamm. »;, 1845, 136. (Compiled from 

 Bach man.) 



Ascomys borealis, Wagn., Snppl. Schreb. lii, 1843, 391. (Compiled.) 



Saceophorus borealis, GTtAY, List Br. Mns. 1843, 149 ("Canada;" mere mention, with bouio wrong syno- 

 nyiiis).— Mriiii', P. Z.S. 1870, 80 (as hosi of CEetrus). 



l\ntdosloma borealis, "Rich. MSS." — Acd. & Bach., Q. N. A. iii, 1853, V.)*, pi. 142. (Description and fig- 

 ure apparently from the original specimens.) 



Thomomys borealis, Baird, Mamm. N. A. 1857, 396, pi. 22, figs. 2a-c. (Account from types of " borealis " 

 and "townsendii", in Mns. l'liila. Acad., with which a Californian specimen is considered 

 probably identical.) — N'r.wn., P. R. E. Rep. vi, 1857, 59 (rests on the Californian specimen 

 jnst mentioned). 



Geomys toumsendii, " Rich. MSS." — Bachm., Jonrn. Acad. Nat. Sci. Phila. 1839, 105. ("Columbia R." 

 Described as distinct from "borealis", with much besitatiou, entirely in deference to Rich- 

 ardson.)— Rich., Zool. Voy. Blossom, 1839, p. 12'.— DeKay, N. Y. Fn. 1842, 92. (Compiled 

 from Bacbman.) — Schikz, Synop. Mamm. ii, 1845, 137. (Compiled.) 



Ascomys townsendii, Wagn., Snppl. Schreb. iii, 1843, 391. 



Qeomys unisulcatus, Gray, "Br. Mns." — Gray, I. c. 



Thomomys rufescens, Maxim., Nov. Act. Acad. G'a?s.-Leop. xix, pt. i, 1839, 383; Arch. f. Naturg. 1841, pt. ii, 

 42 ; ibid. 1861, — ; Verz. Siiug. N.-Am. Reise, 1862, 149, pi. 4, f. 5 (penis-bone). (In the last 

 quotation, tbe generic name is spelled "Tomomys ".) (Missouri region.) — Sciiinz, Synop. 

 Mamm. ii, 1845, 134 (exclusive of the synonym Oryctomys botlw, Eyd. & Gerv.). (Compiled 

 from Maximilian ; California erroneously assiguel as tbe locality.) — Baird, Proc. Acad. 

 Nat. Sci. Pbila. vii, 1855, 335; M. N. A. 1857, 397. (Redescription of specimens from 

 "Nebraska", i. e., Dakota; Forts Pierre, Randall, and Union.) — Baird, P. R. R. Rep. x, 1859, 

 Gunnison's and Beckwitb's Routes, Mamm. p. 8, pi. 10, f. 1 (tbe same). — STEVENSON, U. S. 

 Geol. Surv. Terr, for 1870, 1871, 462 (Wyoming).— Ames, Bull. Minn. Acad, i, 1874, 70 (cata- 

 logued upon presumption of its occurrence in Minnesota). — Allen, Proc. Bost. Soc. xvii, 

 1874, 43 (Yellowstone River) ; Bull. Ess. Inst, vi, 1874, 56, 61, 65 (rather supposed than 

 known to be tbis species). 



Geomys rufescens, LeConte, Proc. Acad. Nat. Sci. Pbila. vi, 1852, 161. (Redescribed from types of " bore- 

 alis " and " townsendii ", iu Philadelphia Academy, marked " Columbia River ".) 



Ascomys rufescens, Wagn., Snppl. Schreb. iii, 1843, 387. 



Geomys ( Thomomys) rufescens, Giebel, Siiug. 1855, 530. 



Thomomys "fulvus ", Merr., Aun. Rep. U. S. Geol. Surv. Terr, for 1872, 1873, 665. (Ncc Woodb.) 



Diagnosis — Coloration almost exactly that of the house-rat (Mus decu- 

 manus) — sometimes assuming a more reddish phase, occasionally blackish- 

 plumbeous ; tail and feet white, and much of the chin, throat, and breast 

 white in irregular patches, where the fur is white to the base. No sooty- 

 blackish about the mouth-parts; no obvious distinction in color between the 

 pouch and its surroundings; no strongly-pronounced reddish-brown on the 

 under parts; general tone of coloration never decidedly tawny. Ears set in 

 a small blackish area. Length, 6 to 8 inches; tail, 3 inches or less, decidedly 

 less than half the length of head and body ; fore and hind feet (claws included) 

 approximately equal to each other, 1.10 to 1.25; longest fore claw little less 

 1 han the length of the rest of the hand, about 0.50. Mammae, 6 pairs — 2 pairs 

 inguinal, pectoral, and axillary, respectively. In some specimens, however, 

 one or two pairs apparently fail to develop, generally the axillary ones. 



