[Read before the Philosophical Institute of Canterbury, 1st October, 1874.]
Mr. Potts, in his notes on the birds of New Zealand read before the Philosophical Institute of Canterbury in December last (Trans. N.Z. Inst., Vol. VI., pp. 139–153), takes exception in the following terms to my treatment of his supposed new species of Tern, (Sterna alba):—
“The white Tern seen by the writer on the Ashburton, and described by him in Trans. N. Z. Inst., Vol. III., is quietly placed by Dr. Buller with S. nereis, to which he gives the name of the Little White Tern. This fine white Tern was seen on the Waitangi River by the Hon. G. Buckley and others. Last month (20th November) a pair were seen flying up and down the course of that great river.
On a careful reperusal of Mr. Potts' published notes I acknowledge that I was wrong in referring his bird to Sterna nereis, but until a specimen has been actually obtained and examined it is impossible to admit it into our list as a recognized species. Mr. Potts, in his original notice (t.c., p. 107), merely described the bird as it appeared to him on the wing. He stated that the whole plumage was white, and that “the bill appeared to be light-coloured,” adding that these “observations were made during its rapid movements.” He gave no hint whatever of its size, although he now refers to it as a “fine white Tern,” as compared with the Little White Tern (Sterna nereis).
On such a description as this I fear that Mr. Potts' claim to the discovery of a new species would scarcely be admitted by ornithologists at home; and even if it were the name of Sterna alba has been preoccupied by Gmelin. The bird may turn out, as Mr. Potts himself suggests, to be identical with a species recorded from Norfolk Island. But if, on further acquaintance, it should prove to be new, I think we cannot do better than associate Mr. Potts' own name with it in lieu of the one he has proposed.