TUKD1D.E — THE TIIUUSIIES. 



Caban., and alvirr, IJaiid. The first-immcMl is totally unlike the R.^t, 

 which are nioic tdosely related in ai>pearanee. 



In studvini,^ carefully a very large series of specimens of all the species, 

 the l'on(nvini4 facts become evident : — 



1. In autumn and winter the "olive" coh)r of the plumage assumes a 

 browner cast than at ot^er seasons ; this variation, however, is the same 

 in all the sjiecies (and varieties), so that in autunin and winter the several 

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



Of these five species, two only {palhisi 

 and siraiHsoni) inhabit the whole breadth 

 of the continent ; and they, in the three 

 ?\uinal rnninces over which they ex- 

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

 rieties" characteristic of each region. 

 The first of these species, as the paJIcd 

 var. jiiillasi, extends westward to the 

 liocky Mountains, and migrates in winter 

 into the South ; specimens are very nuich 

 browner in the winter than in spring ; 

 but in the liocky ^lountain region is a 

 laruer, <;raver race, the var. ainltihoni. 

 This, in its migmtions, extends along the 

 central mountain region through ^lexico 

 to (ruatemala; sj)ecimens from the northern and southern extremes of this 

 range are identical in all the specific characters ; but the southern specimens, 

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

 (spring birds) ; an autumnal example from Cantonment Ikirgwyn, X. M., is 

 as l>rown as any Central American specimen. Along the IVicific Province, 

 from Kodiak to Western ^lexico, and occasionally stra^nlinu: eastward toward 

 the Itockv Mountain svstem, there is the var. nanus, a race shmlln- than 

 tlie var. pallasi, and with much the same colors as var. ojidahoni, though the 

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

 as in the others, there is no ditierence in size between si)ecimens liom 

 north and south extremes of its distribution, because the breeding-] dace 

 is in the Xorth, all Southern specimens being winter sojourners from their 

 Xorthern birthplace. 



The T. sicaiiisoni is found in abundance westward to the western limit 

 of the liocky ^lountain system ; in the latter region specimens at all 

 seasons have the olive of a clearer, more greenish shade than in any P^asterii 

 examples; this clearer tint is analogous with that of the liocky ^lountain 

 form oi iKiUasi {aiuUihoni). In precisely the same region inhabited by the 

 pallasi var. nanus the sirainsoal also has a reju'esentafive form, — the var. 

 if sf I' /at us. This resembles in pattern the var. swainsom) but the olive above 

 is decidedly more rufescent, — much as in liocky ^b)uiitain specimens of 



Turilus ustulatus. 



