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buoyant as a feather in the air ; but its flight is swift, and it turns with ease, and when it pounces 

 down on its prey it drops like a stone from the air, where it usually hovers for a moment before 

 darting down. It breeds in marshy localities, where it builds a tolerably well constructed nest 

 of grass and marsh-plants, in which it deposits three eggs. M. A. Benzon, writing to me from 

 Denmark respecting the occurrence and nidification of the present species, says : — " It arrives 

 here late, not till the latter end of May, and leaves again in September. At Soborg Mose, near 

 Copenhagen, there is a breeding-place of the Black Tern, where, should one be in search of the 

 eggs of Podiceps rubricollis, Cygnus olor, Circus rufus, and Fulica atra, about the middle of 

 May, one will, as a rule, not see a single Black Tern ; but should one return a fortnight later in 

 search of eggs of the Shoveller, or to procure the young of the Coot &c, one is sure to see flocks 

 of the Black Tern hovering over the marsh. They nest in a portion of the marsh where scarcely 

 any other species breeds ; and the nests are not collected in close colonies, as is the case with the 

 Black-headed Gulls, but they are somewhat scattered about. I once found a nest of the Red- 

 necked Grebe amongst those of the present species. The nest is placed amongst aquatic herbage, 

 such as Equisetum limosum, Typhia angustifolia, &c. &c, where it is not too dense ; and 1 have 

 on many occasions found the nest almost floating. The nest is constructed of Equisetum limosum, 

 Potamogeton nutans, Typhia, and Polygonum amphibium, sometimes of one, and at others of several 

 of these plants ; and it is lined with fine Equisetum bents. I have found eggs from the 1st of 

 June to the 6th of July, on which latter day I found at the above-named locality several new 

 nests without eggs, whereas at the same time most of the young birds had already left the other 

 nests, and only two contained strongly incubated eggs, and a third a rotten egg and one young 

 bird ; a second young bird was swimming outside the nest. This may tend to show that the 

 present species breeds twice in the season, or that young pairs do not breed so early ; or else it is 

 possible that the owners of these nests had their first eggs destroyed by a Crow or a Harrier. 

 Three eggs are the number deposited by the present species ; and to this number they appear 

 always to adhere. With regard to its food, it appears to consist of worms, insects and insect- 

 larvae, and various aquatic animals : it appears even to feed on leeches ; for in Jutland, near 

 Yiborg, where I have an interest in some leech-pools, the overseer has continually to drive away 

 the Black Terns, which always come in companies of four or five individuals to the ponds at such 

 times as the leeches are moving about, whereas they never fly down to the ponds after fish." 



I possess a tolerably large series of the eggs of the present species, which vary somewhat 

 both in colour and markings. The ground-colour is lighter or darker ochreous clay, in one or 

 two almost olivaceous ochreous ; and the markings consist of dark purplish grey shell-blotches, 

 and blackish surface-spots and blotches. Some are somewhat sparingly spotted, whereas others 

 are very densely blotched. In size they vary from l-j§ by ff inch to lf^ by 1^ - inch. 



The specimens figured are an adult bird in full breeding-plumage from Denmark, and a 

 winter specimen from Southern Europe ; and, though I have described a specimen from Spain, I 

 have deemed it best to figure the paler North-European bird, as it differs most from the extreme 

 dark form found chiefly in the Nearctic Region. 



In the preparation of the above article I have examined the following specimens: — 



2l2 



