Birds. 



6719 



it made the fourth species of Hirundine that were there skimming 

 round this house, and the fifth I had noticed within half-an-hour. 



"Cypselus niger, from its having escaped your observation, as well 

 as that of your coadjutors, I long considered as probably a rare and 

 very occasional visitor. 



"On the 9th of June last we had much rain, heavy clouds which 

 did not disperse, and much thunder; when, hearing the scream of 

 Acanthylis, as well as the cry of Chordeiles, I went out to watch them, 

 and see whether there was any probability of either giving me a shot. 

 To my surprise Acanthylis seemed, as I thought, much smaller than 

 usual, and the curved wings did not form the remarkable arch I was 

 so familiar with. A great number of swifts were dashing about over 

 the meadow, in the violent, impetuous way they do on rainy after- 

 noons, when, one passing between me and a tree, followed by an 

 Acanthylis, I saw there were two species. The new one was smaller, 

 quite black, had no white collar, and seemed to me grayish about the 

 head and throat, points which seem to agree with your description of 

 Cypselus. I immediately went for my gun, but on returning they 

 had got high, and I fired one or two ineffectual shots. Their flight 

 and habits are, however, very different from those of Acanthylis. On 

 the afternoon in question, and since, I have observed when there is 

 little or no wind, they constantly practise a manoeuvre 1 would repre- 

 sent by the accompanying diagram. By the 

 dotted line I mean a beating rise ; by the 

 entire, a festooning fall ; — a habit very 

 common with the martins, but one 1 have / 

 never observed Acanthylis adopt. These y 

 latter birds soon collected into column ; and 

 then the numbers of the other species, about thirty, became apparent, 

 who had not, evidently, the slightest inclination to practise a similar 

 movement, but continued hawking in an irregular body the rest of the 

 afternoon. I noticed a pair pursue, when the nuptials evidently took 

 place. Their motions were extremely rapid and irregular, not unlike 

 birds fighting; and the scream was not so shrill as that of Acanthylis, 

 and broken into separate syllables. I have since, when here, seen 

 them almost every evening, and for the last week have been watching 

 for a shot, but in vain. Except at the above-mentioned time, I have 

 never seen them, except just about an hour before sunset, when they 

 continue hawking till they are joined by numerous high-flying bats, 

 and the light is too uncertain to distinguish them. They generally 

 appear about half-a-dozen together, and glide along slowly, on 



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