BCniRIDi^— AHCTOMYH MONAX. 



OH 



Sjiermop/iilun, difl'oriiig Rcnrccly morn tVoiii Sciurun tlinn do llic OIohixtiiui- 

 pliiline forms of Spcrmophilux. On IIk; other Imiiil, it is in tlicso fniturcs 

 that Cynoinys is lii>,'lily 8|H,'(;ialize(l. Tlio skull of AirtowyK, vicwcrt in its 

 totality, (liiTeri:) from the Sciiirine forms of Sperwo/ihi/us mainly in its very 

 much larger size, nn<l in its much strnightcr tlorsal outlino. This, in part, 

 results from the (lc|»re8sion of the interorhitnl region, nnil in part from the 

 great development of the occipital crests, naturally correlating witli the large! 

 size and heavier form of tiio animal. The triturating sirtiice of the molar 

 teeth in Arclomy$ presents two deep transverse grooves, extending from the 

 outer edge to the middle of the tooth, instead of three, as in Ci/nonn/x, 

 agreeing in this respect with Spermophilux, Tamias, and Sciurm. 'J'he first 

 upper premolar is relatively not larger than it usually is in Spernuqihiliig, and 

 is smaller, absolutely as well as relatively, than in Cynomyx. 



The genus Arcfomyn omhraces the largest members of the Sciurida", 

 and, excepting Castor, the largest of the existing North American liodentia. 

 The group is represented throughout the northern and middle portions of the 

 northern hemisphere, and is not found elsewhere. In the present paper, 

 three species are provisionally recognized as North American and as distinct 

 from their nearest Old World allies. 



ARCT0MY8 MONAX (Linn.) Schreber. 

 Woodcbuck. 



ilut nOMU LiNNiEUS, Syst. Nat. lUlli e<l. !, 17fiS, i'fi; lath ed, i, SI (bailed wboll; on Edwnrdb'a drscrip- 

 tion and flcnm of a upcciuipu from Marylaud).— Pallas, Nov. Bpec. Ulires, 1778 (iu part 

 on);).— BoDDJiitT, " Elench. Anini. i, 17S4, 105." 



OUt monax Erxlkiikn, Syiit. Auini. 1777, 361 (in part only). 



Arclomft moiiaz Sciiredkii, SUugut. iv, 7;i7.— Shaw, Gon. Zoul. ii, IfiOS, 117.— F. Cuvieb, Diet, dra Sci. 

 . N»t. ixlx, \»£\, 168.— Wakdrn, Desorip. den fitats-Unis, v, l?aO, 627.— Dksmakkbt, Nonv. 

 Diet. d'Hiat. Nat. xix, ItJlS, :IU ; Mam. 1832, :)28 (in part only).— Sahink, Truna. Liun. Sue. 

 xiii, 1888, 588.-HAIILAN, Faun. Amer. lH2r>, 158.— Godman, Amor. Nat. Hi»t. il, 182ti, 100.— 

 I. Oeo- . Diet. Clow. d'Hiiit. Nat. x,^ 1887, 186.— HAMir.TUN-SMiTii, Griflltb'H Cuvier'H 



An. K 1887, 170 (with plate); v, 1887, 244.— Richardson, Fann. Bor.-Amcr. i, 1829, 



163 (compiled, chiefly from Godman).- Fischkh, Syuop. Mnm. 1889, :t48.— Emmons, Q<">d. 

 Haaa. 1840, 64.— Dk Kay, New York Zooi. i, 1848, 6-t, pi. ■ ri, Bg. 4.— Thompson, Nt. \l\»U 

 * Vmmont, 1848, 44.— Waoneii, Snppl. Sobreber'a 8Un|{et. iii, 1843, 8,''ig (in part).— SciilK/., 



8yn. Mam. Ii, 184r>, 61.— Auduiion & Baciimak, Quad. N. Amur, i, 1849, 17, pi. ii.— Gikbet., 

 Siiaget. I8u.'>,6-iU(in purt nuly , includes all tho American species).— Krnnicott, Trans. III. 

 State Agr. Soo. i, 18c5, aO; U. 8. Pat. OIT. Rip. Agr. 18E6 (16C7), 88, pi. x.— llAiKD.Mam. 

 N. Amer. I857,3;«),pl. !.lix, Sg. 1 (kkull).—TllOMA8, Trims. 111. Stale Agr. Soc. iv, 1860,657.— 

 Ross, Eilinh. New Phil. Jouru. xiii, 1861, 168; Ciinnd. Nnt. and Gcol. 1861, 434 ; Nat. Hist. 

 Ruv. 1868, 874. — Maximilian, Arch, f Naturgcsch. 1861, 9:1. — Ali,kn, Bull. Mns. Cump. Kool. 

 i, 1669, 380 (Massachusetts) ; Pruc. Bost. See. Nat. Hist, xiii, 1870, 190 (Iowa); xvi, 1874, 

 294.— Copk; Proe. Amer. Phil. Soc. Phila. xi, 1869, 173 (fossil; bone-caves, Virginio).— Gu.- 

 . pin; Proo. and Trans. Novn Scotia Inst. Nat. Sci. ii, pt iii, 1870, 16.— Adams, Field and For- 

 est Rambles, 1873, 100, 896 (New Brunswick). 



