HY DROCHELIDON NIGRA. Black Tern. Sterna fissipes, et nevia, Linn. Syst. Nat. (1766), tom. i. pr 22st mgra, Briss. Orn. (1760), tom. vi. p. 211. —— plumbea, Wils. Am. Orn., vol. vii. 1831, pl. Ix., young. Hydrochelidon nigra, Boie, Isis, 1822, p. 563. nigricans, Brehm, Vog. Deutschl., p. 794. obscura, Brehm, ibid., p. 795. Jissipes, G. R. Gray, Gen. of Birds, vol. iii, p. 660, Hydrochelidon, sp. 5. plumbea, Lawr. Gen. Rep. 1858, p. 864. Viralva nigra, Steph. Cont. of Shaw’s Gen. Zool., vol. xiii. p. 167. Tue generic term Hydrochelidon was instituted by Boie for a small section of the Sternide possessing certain peculiarities of structure accompanied by an equally peculiar style of colouring, and whose habits and economy are unlike those of the other members of their family, from which they also differ in the kind of situations they frequent. The ordinary Terns or Sea-Swallows, genus Hirwndo, are true sea-birds, which either retire to shingly beaches or ascend the larger rivers with banks of a similar character for the purpose of breeding, incubate their two eggs on the bare ground, fly with a laboured flapping motion of their wings, and descend upon their piscine food with a perpendicular stoop like that of the Kingfisher. The members of the genus Hydrochelidon, on the other hand, frequent the inland fresh waters (lakes and rivers) rather than the open sea, feed principally upon large winged insects, which they take in the air, and deposit three or four eggs in a nest of weeds placed in a tuft of grass in the midst of reed-beds. The true sea-Terns have short webbed feet, while the feet of the marsh-Terns, as the birds of the present form are called, are more lengthened and have the interdigital membrane but little developed. The Black Tern, which is a migrant, comes to us in the spring from a warmer climate, and, if any suitable locality be left in which it may remain unmolested, will reproduce its kind during its stay. On this point Mr. Stevenson, of Norwich, writes to me :—*‘ Although this species formerly nested in considerable numbers, both on our eastern broads and in the fens of the western part of Norfolk, it has almost ceased to breed in the county. I know of but one or two solitary instances of a pair remaining to breed with us during the last few years ; Mr. Newton informs me that in the spring of 1852, owing to the extent of land then under water, from the immense floods of the previous winter, two or three pairs bred in Feltwell fen, where they had not been known to remain for some years. Draining, and the abominable system of indiscriminate egging, are the principal causes why this bird, the Black-tailed Godwit, and other species, now proceed further north. The old birds regularly appear on the coast every spring during the months of April and May, and again with their young in autumn (August, September, and October). The Black Tern is said to have formerly bred at Winterton, near Yarmouth ; and Lubbock, in a communication to Yarrell, says, ‘ the great breeding-place, in a wet alder-carr at Upton, where, twenty years back, hundreds upon hundreds of nests might be found at the end of May, has been broken up some years.’ ” During the numerous visits I have made to the middle portion of our beautiful Ubsiies in the month of May, for the last forty years, I have seldom missed seeing the Black Tern hawking over the reaches in the neighbourhood of Maidenhead, Cookham, and Marlow. At that season they are apparently passing over our island from the Bristol Channel to some eastward localities, and they merely stay for a few hours, in their course down the river, one day at Henley, the next at Maidenhead or Windsor, thence proceeding to the Nore and other parts of the eastern coast. From the 10th to the 19th of May, 1866, several solitary boat; and a similar occurrence took place in the same locality ue succeeding year. Occasionally I have seen the Common Tern, the Arctic Tern, and the present species in the same reach at one time; an example of each of the three species, all of which fell to my own gun in 1866, may be a at Taplow Court, Mr. C. Pascoe Grenfell having kindly accepted them as a memento of these bus hes y occurring in his neighbourhood. In autumn the young a the Black Tern sometimes occurs; and the flying figure in my Plate was taken from an individual killed in the same locality. oe oe Nothing can be more easy than to distinguish the Black Tern, on the wing, from t ; x oe a puis i so different are they in appearance that, if seen flying together at the end of a reach half a mile : ‘There is one of the black Terns.” individuals passed my fisherman will remark, As before stated, the flight of the typical or sea-Terns appears to be of a laboured character ; the marsh- C : 5