TURBID. THE THRUSHES. 67 



and his absence would create a void in the ranks of our birds, 

 which would be felt by every one who cherishes memories of his 

 boyhood days. 



GENUS SIALiIA SWAINSON. 



Sialia SWAINSON, Zool. Jour, iii, Sept. 18'47, 173. Type. Motacilla sialis LINN. 



"GEN. CHAK. Bill short, stout, broader than high at the base, then compressed: 

 slightly notched at tip. Rictus with short bristles. Tarsi not longer than the middle toe. 

 Claws considerably curved. Wings much longer than the tail; the first primary spuri- 

 ous, not one fourth the longest. Tail moderate; slightly forked. Eggs plain blue. Nest 

 in holes. 



"The species of this genus are all well marked, and adult males 

 are easily distinguishable. In all, blue forms a prominent feature. 

 Three well-marked species are known, with a fourth less distinct. 

 The females are duller in color than the males. The young are 

 spotted and streaked with white." (Hist. N. Am. B.) 



COMMON CHARACTERS. Adult male bright blue above, beneath cinnamon and white (S. 

 sialis), blue and chestnut (S. mexicana'), or blue and white (S. arctica); adult female with 

 the blue above confined to the wings, rump, and tail, the upper parts being grayish, the 

 lower parts paler and duller than in the male (in S. arctica, breast, etc., grayish drab). 

 Young, with the grayish or dusky upper parts spotted or streaked with whitish, and 

 the whitish lower parts squamately spotted with dusky. 



a 1 . Breast and sides chestnut or cinnamon. 



1. S. sialis. Throat cinnamon, like the breast; belly white; upper parts cobalt-blue. 

 Hab. Eastern North America. 



2. S. mexicana. Throat deep blue; belly grayish blue; upper parts rich smalt-blue, 

 the back usually with a chestnut patch. Hab. Western U. 8., chiefly in the val- 

 leys. 



o 2 . Breast and sides turquoise-blue. 



3. S. arctica. Upper parts rich azure-blue; belly white. Bab. Western U. S., chiefly 

 on the higher mountains, and northward to the interior of British America. 



The three known species of this genus are included in the above 

 synopsis for the reason that two of them have already been recorded 

 as occurring in the State, while the third (S. mexicana) is said to 

 have been taken in Iowa, and may therefore possibly, like other 

 western species, occasionally straggle to Illinois. 



The females of the three species differ from one another in much 

 the same characters as those which distinguish the males, though the 

 colors being much duller the differences are far less striking. 



