TUUDID.K — THE THRUSHES. 



5 



Caliaii., and alirirv, liiiinl. The first-naiiuMl is totally unlike the rest, 

 wliicli arc moie elosely related ill a]'i)eaiaiiee. 



In studyinj;' carel'ully u very larj^e series ul' specimens of all the species, 

 the i()U()\vin;4- facts become evident : — 



1. In autnmu and winter the "olive" cohir of the ])lnmajj:e assumes a 

 browner cast than at other seasons ; this variation, however, is the same 

 in all the species (and varieties), so liiat in antnnui and winter the several 

 species diller from each other as nuich as they do in spring and summer. 



Of these live species, two only (iKil/nsi 

 and siruiiisuni) inhaliit the whole breadth 

 of the continent; and tliey, in the three 

 Faunal Trovinces over which they e.\- 

 tend, are niodilied into " races " or " va- 

 rieties" characteristic of each region. 

 The first of these species, as the pKlhml 

 WAY. piillasi, extends westward to the 

 liocky Mountains, and migrates in winter 

 into the South; specimens are very nuicli 

 browner in the winter than in spring ; 

 but in the Hocky Mountain region is a 

 larger, grayer race, the var. ainlnJiuiti. 

 This, in its migrations, extends along the 

 central niouutaiu region through Mexico 

 to (luatemala; si»ecimens from the northern and southern extremes of this 

 range are identical in all tlie sjiecilie characters; but the southern sjiecimens, 

 being in the fall and winter dress, are Imjwner in color than northern ones 

 (siting birds); an autumnal example from Cantonment IJurgwyn, \. ~S\., is 

 as lirowu as any Central American specimen. Along the raciiic Province, 

 from Kodiak to Western Mexico, and occasionally straggling eastward toward 

 the Kocky Mountain system, there is the \ar. iKnina, a race niixillrr tiian 

 the var. imUdni, and with much the .same colors as var. niiiluhoiii, though the 

 ndbus of the tail is deeper than in either of the other forms. In this race, 

 as in the others, there is no dillerence in size between s])ecimens from 

 north and south extremes of its distribution, becausi; the breeding-] ilace 

 is ill the Xortli, all Southern sjnicimeiis being winter s(jjourners from their 

 Xorthern birthplace. 



The T. Hwa'uisoni is found in abundance westward to the western limit 

 of the Ifocky ^Mountain system; in the latter region s[v('ciiiiens at all 

 seasons have the olive of a clearer, more greenisli sliade than in any Kaslern 

 examples; this clearer tint is analogous with that of tiie IJucky Mountain 

 fnrm oi poUntii {<(ii(liih(ini). In precisely the same region inhabiteil by the 

 pallasi var. ndiius the siridnsdiii also has a representative form, — the \ai'. 

 iis/ii/otiin. This re.semliles in pattern the var. niniiiixoni. Imt the olive abov(> 

 is decidedly more rufesceiit, — nuicii as in Ilocky Mountain sperimeiis of 



TtirilKs ustulatus. 



