﻿stejneger] birds of genus cinc] i 4 2 3 



and tail, 1)ui these features are plainl) secondary developments. The 

 similarity of these young birds is so great that added to the many 

 structural characters pointed out by Professor Baird I am convinced 

 that Cine! us lias sprung" from the same root as the other two, and 

 that its many peculiarities are mere adaptations to its aquatic 

 habits. Even the curious " dipping " motion which in a great mea 

 ure has helped to associate it in our minds with the wrens, connects 

 it equally well with the Saxicolas. 



The latter are exclusively ( )ld World birds except the typical 

 species Saxicola oenanthe which 1 have shown to be a comparatively 

 recent immigrant into this continent (Proc. U. S. Nat. Mus., XXIII, 

 1901. pp. 473-48] ). The blue-birds, Sialia, on the other hand, are 

 North American. While it is true that they follow the elevated 

 regions down to the isthmus of Panama, it is also true that they 

 have no Neotropical relatives, that they belong to the birds charac- 

 teristic of the Nearctic region — or subregion ! Sharpe has recently 

 affirmed that the beautiful Himalayan bluebird, Grandala ccelicolor, 

 tested by the characters I have given for the Turdidse, " shows great 

 affinity to Sialia" (Hand-list Birds, iv, 1903, p. 184), and he even 

 enumerates it between the two nearctic genera Sialia and Ridgwayia 

 in order to express this close affinity, 1 Sharpe also places the 

 genus Catharus in close proximity to the bluebirds. This genus 

 inhabits the elevated portions of Mexico and Central America south 

 into northern South America along the Andes as far as Peru. 

 Nevertheless, it is not a neotropical genus ; its affinities are dis- 

 tinctly holarctic whether we adopt Dr. Sharpe's view that they 

 belong to the Sialieae or mine (Proc. U. S. Nat. Mus., v, 1882, p. 

 467), that they are part of the same group which includes the Old 

 World nightingales, blue-throats, etc., viz., the Luscinieae. 



Bearing these facts in mind I have therefore no hesitation in 

 affirming that ductus is of palearctic origin. 2 It remains only to 

 fix upon a more restricted and definite region as its probable original 

 starting point. 3 



1 Seebohm even placed Grandala in the genus Sialia, 



2 It will be seen that on the whole I agree with Seebohm, Brit. Birds' Eggs, 

 I, 1883, p. 253, and Scharff, Hist. Europ. Fauna, 1899, p. 255. 



3 It may help to understand the following better if I give a condensed 

 synopsis of the various forms (31) now recognized by advanced ornitholo- 

 gists. No attempt has been made to subordinate them, and their unit names 

 are enumerated chronologically in each main group. 



Genus Cinclus Borkhausex, 1797 

 a 1 Coloration of young more or less squamate (Old World). 

 & 1 Color of adults more or less uniformly fuscous. 



