ON THE GENUS HARPORHYNCHUS 61 



lence. The arcuation of the bill proceeds pari passu with its 

 elongation : the shortest bills being the straightest, and con- 

 versely. There is also a curious correlation of color with shape 

 of bill 5 the short-billed species being the most richly colored 

 and heavily spotted, while the bow-billed ones are very plain, 

 sometimes with no spots whatever on the under parts. 



The genus is specially interesting in the present connection, 

 since it reaches its highest development in the Colorado Basin, 

 where nearly all the known species occur, some of them in 

 abundance ; while several of them are entirely confined, so far 

 as we now know, to this region. As much can be said of no 

 other genus. Harporliynclms is, in fact, the leading feature of 

 the Colorado avifauna, whether we consider the relative num- 

 ber of species there represented, or the extremely local distribu- 

 tion of some of them. The fringilline genus Pipilo offers much 

 the same case ; and there is a further singular parallelism be- 

 tween the two. Both are represented, in the United States at 

 large, by a single species, heavily and even richly colored in 

 comparison with the pale dull shades of the numerous species 

 or races of the Coloradan region: in both cases, there are 

 species restricted to this Basin; in both, rounded wings shorter 

 than the graduated tail, large strong feet, and terrestrial habits 

 are conspicuous features in comparison with their respective 

 allies. The parallel might even be pushed to the length of 

 recognizing individual species of one genus as representatives 

 of those of the other. Pipilo aberti is the counterpart of R. 

 crissalis, and several others are almost as clearly analogous. 



Brown Thrasher 



Harporliynclms rufus 



TardilS rufllS, L. SN. i. ICth ed. 1758, 169, no. 6 ; 12th ed. 1766, 293, no. 9 (Gates, i. 28). 

 Gm. SN. i. 1788, 812, no. 9. Lath. IO. i. 1790, 338, no. 44. Ttirt. SN. i. 1806, 493. 

 Vieill. OAS. ii. 1807, 4, pi. 59. Wils. AO.ii. 1810, 83, pi. 14. Bp. Journ. Phila. Acad. iv. 

 1824, 33. Bp. Ann. Lye. N. Y. ii. 1826, 75. Less. Tr. Orn. 1831, 408. Peab. Rep. Orn. 

 Mass. 1839, 300. And. OB. ii. 1834, 102; v. 1839, 441, pi. 116.-Ger/. Nanm. iii. 1653, 

 37.Thomps. Vermont, 1853, IQ.Haym. Pr. Phila. Acad. viii. 1856, 288. Gatke, J. f. O. 

 1856, 71 (Heligoland). Gatke, Naum. 1858, 424 (same). Gosse, Alabama, 1859, 54, 295. 



Orpheus rilfllS, 5. V#. FBA. ii. 1831, 189 A T M. Man. i. 1832, 328. And. Syn. 1839, 8S.Aud. 

 BA. iii. 1841, 9, pi. Ul. Wailes, Rep. Mississip. 1854, 319. Pratt.cn, Tr. Illinois Agric. 

 Soc. 1855, 601. Putn. Pr. Essex Inst. i. 1856, 209. Trippe, Pr. Essex Inst. vi. 1871, 

 115 (Minnesota). 



' Orphea rufa, Goui-J, rzs. 1834, 15. 



