■^ 



ii ^- 



388 



MONOGKAl'IIS OF NOKTR AMERICAN RODENTIA. 



jjalate in Iljjstrix is broad and flat, and of uniform breadtii ; in Erethizon it 

 is narrowed anteriorly, and rises abruptly in front of the molr.rs, and between 

 the mohir series presents u prominent, central, ragged keel. Without 

 going into a further comparison, it may suffice to stato that the structure of 

 the sUull in the two forms differs markedly in nearly every detail. 



To the old Linnean genus Hystrix were for many years referred all the 

 known Porcupines from both tlie Old and the New World. The group was 

 iirst dismembered by M. F. Cuvier in 1822, who divided the Old World 

 species into two groups, Hysfrix and Acanlh'wn,* and the New World species 

 into three, Erethizon, Synetheres, and Sphinguius (" Sp/itggurus"). Brandt, in 

 1835, called special attention to the cranial differences characterizing the 

 01(1 World and New World species, and adopted Cuvier's genus Erethizon 

 for the North American species, but united the two South American genera of 

 Cuvier into the single genus Cercolabes, which groups have since been com- 

 monly retained, with the limitations and names given by Brandt. Cercolabex, 

 however, seems divisible into two generic groups, for which Cuvier's prior 

 names should be retained.! Cho'tomys was established by Gray in 1843 for 

 the Hystrix suhspi}wsa of earlier authors. 



• The genus Erethizon is confined to the middle and northerly portions of 

 the North American continent, and is represented by a single species, divisi- 

 ble into two easily distinguished geographical varieties or subspecies. 



ERETHIZON DORSATUS (Linn.) F. Cuvier. 

 Var. DORSATUS. 

 Canada Porcupine. 



Hyatrix dortala Linn., Syst. Nat., e«I. x, i, 175tf, 07 | e<l. xii, i, ITfifi, "C— FonsTF.B, Thil. Trans., Ixii, 

 1773, ;i74.— KnXLKiiEN, SyHt. Uog. Aiiiiii., 1777, 345.— Gmki.in, Syst. Nat., i, 17H4, 110.— 

 SciiHEnEU, .Siinget., iv, 171(2, 00">, pi. clxix.—Sluw, Gon. Zool. Miini., ii, 1801, 13, pi. cxxv.— 

 Kuiii., BL'itriigi' ziir Zoologip, 1820, 70.— Dksmaisest, Mnni., 1822, :i4.'>.— J. Saiiink, Franliliii'n 

 .Journey to the Polar Sen, 1823, 0(54.— CozzENS, Ann. N. Y. Lye. Nat. Hist., i, 1823, 191.— 

 IIaiilan, F.inna Aiucr., 182.'5,1U0.— Godman, Anier. Nat. Hist., ii, 1820, 50. — GiiiniTn'sCinii-r 

 iii, 1827,200; v, IS'27, 2C:i.— FtsciiEn, Synop. Mam., 1829, 3f)8.— Emmonb, Qnnil. JIn8.t., 1840, 



• 71.— TiioMi'.soN, Hist. Vermont, 1842, 47.— AuDunoN and Bachman, i, 1843, 277, pi. xxvi. 

 Krelhlzon dorsatimV. Ctn'iEn, Mdm. dn Mus., ix, 433, pl.xx, flgs. l,2,S(8knllamlmolar). — nRANUT, M<5m. 



Acad. St. P<Ster8bourg, 1835, 387.— WatkiiiioC8E, Nat. Hist. Mam., ii, 1848, 438.— Giehel, 

 Siinget. 185.'), 478.— Wagneh, Suppl. Sohrebor's Siingot., iv, 1844, 37 (in part). — Baird, Mam. N. 

 Amer., 1858 ."iCS.— Ai.lkn, Bull. Miis. Comp. Zocil., i, 1809, 2.15. 



• Acanthion, although applied to species with the frontal region of the skull only moderately swollon, 

 lias not been considered by moat later writers as genorically separable from Jlgitrix, the second of tlio 

 two genera of Hyetricitxe commonly recognized being Atheruro, flnst characterized seven years later hy 

 M. 0. Cuvier. 



t Alston (Proc. Zoiil. Soo. Lend., 1870, 94) considers Sijnethrret and Sphlngurut as being not gencrio- 

 nlly separable ; ho adopts Sphingurua as the tenable name of the group, and hence changes the name 

 of the subfamily from Cercolabiiiw to Sphingurina;, although Synelherea has the precedence in Cuvier's 

 memoir. Gervais, as early as 18.'>2, used the name Symtherina as a subfamily name for the New World 

 Porcupines, which name hence has many ycare' priority over SpUngurino!. 



