SPRAGUE'S MISSOURI LARK. 335 



discover with the eye, and at times some of them actually disappearing from 

 our sight, in the clear thin air of that country. 



On the ground they run prettily, sometimes squatting to observe the move- 

 ments of the intruder, and at times erecting their body fronting the pursuer. 

 After procuring a good number of them, our anxiety about discovering their 

 nest was relieved by Mr. Sprague, who brought us one containing five 

 eggs; and afterwards we procured several young fully fledged. 



On first rising from the ground they fly in so deep and undulating a manner, 

 as almost to preclude their being shot on the wing; and this they continue to 

 do, forming circles increasing in extent until about one hundred yards high, 

 when they begin to sing, and continue to do so for fifteen or twenty 

 minutes at a time, and then suddenly closing their wings, they glide down 

 on the prairie below. We had not been long in chase, ere we discovered 

 that they could be approached much easier by riding after them in a small 

 wagon, and on several excursions we all procured specimens. Sometimes 

 when rising from the ground, as if about to sing, for some forty or fifty 

 yards, they suddenly pitch downwards, alight, and run or squat, as already 

 mentioned. 



The nest of this species is placed on the ground and somewhat sunk in it. 

 It is made entirely of fine grasses, circularly arranged, without any lining 

 whatever. 



The eggs, which usually are four to five in number, average seven-eighths 

 of an inch in length by five-eighths in breadth, are smooth and dotted 

 minutely all over, giving them a general greyish-purple hue. The young, 

 after being hatched, follow the parents on the ground, and are fed with the 

 smaller seeds of grasses, and gradually with insects, &c. They were already 

 found in loose small flocks of eight to a dozen before we left Fort Union on 

 the 16th of August, and some had began their migrations southward, as well 

 as many other species of birds. 



Sprague's Missouri Lark, Alauda Spragueii, Aud. 



6, 101. 



Found on the prairies near Fort Union. Habits somewhat similar to the 

 European Sky-lark. Abundant. 



Adult Male. 



All the upper parts are light reddish-brown, streaked with blackish-brown; 

 the fore neck pale yellowish, streaked around the upper part of the breast 

 with elongated brownish-spots. Sides deeper, or nearly reddish-brown. 

 Second primary longest, the first rather longer than the third. Secondaries 

 nearing the end of the primaries to within three and a half eighths of an 



