1871.] MR. NEWTON ON A SEXUAL PECULIARITY IN A DUCK. 649 



8. On a remarkable Sexual Peculiarity in an Australian Spe- 

 cies of Duck. By Alfred Newton, M.A., F.R.S., 

 V.P.Z.S. 



[Received November 6, 1871.] 



It is now getting on for nearly a year since I received from the 

 Secretary the bodies of two Australian Ducks which had recently 

 died in our Gardens. The species to which they belong is that 

 known as "Anas punctata, Cuvier" * — a name I take as given, not 

 having satisfied myself that it is one which ought to be used. 



The specimens, the skins of which I now exhibit, were iu the di- 

 verse plumage which has been fully described as characterizing the two 

 sexes ; and I confess that from such knowledge as I had of the internal 

 structure of the section of the family Anatidce to which this species 

 obviously belongs I never anticipated finding any thing sufficiently 

 novel in the present case to justify me in bringing it to the notice 

 of the Society. How agreeably disappointed I was will be seen. 



Being much engaged by other occupations, and, as I have said, 

 not expecting any remarkable feature to be presented, I sent the 

 specimens to Mr. Baker of Cambridge, requesting him to skin them, 

 ascertain the sex of each, and prepare the sternums and tracheas. 

 This he did ; and when I add that I have known Mr. Baker for more 

 than twenty years to be a man on whom I can fully rely, I trust no 

 suspicion of the possibility of error may cross the minds of zoologists 

 in consequence of my not having myself made the dissections. 



The sternum of every species of freshwater Duck that I have pre- 

 viously seen presents at its posterior end a deep fissure on either 

 side ; but this fissure is occasionally so much bridged across by the 

 prolongation of its inner margin in an outward direction that I have 

 been fully prepared to find the junction completed in some specimen, 

 either as a characteristic of the species, as it is in some of the diving 

 Ducks, or even as an individual peculiarity. I was therefore not 

 much surprised to see complete fenestration effected in one of the 



* Two perfectly distinct species have had the name Anas punctata applied to 

 them — the subject of this notice, and one from South Africa described by Burchell 

 in 1822 (Travels, &c. i. p. 283, note). The earliest publication I can find of 

 "Anas punctata, Cuv.," is by Mr. G. R. G-ray in 1844 (List of &c. Anseres, 

 p. 134) ; but whence he obtained the information he cannot, as he kindly tells 

 me, recollect. Lesson in 1831 (Tr. d'Orn. p. 634) has an "Anas punctata, Gal. 

 de Paris," which, though he suggests it may be one of Horsfield's species, is 

 probably the same as the one meant by Mr. Gray, since Dr. Pucheran (R. Z. 

 1850, p. 540) has identified the specimen which bore that name in the Taris 

 Museum with the Australian species figured under the same designation by Mr. 

 Gould (B. Austral, vii. pi. ). In Dr. Hartlaub's 'Index' to Dr. Pucheran's 

 valuable paper (J. f. 0. 1855, p. 419) notice of this case is unfortunately omitted. 

 L T nless it can be shown that Cuvier's name was published before Burchell's (and 

 this is extremely unlikely), punctata must of course be kept for the South-African 

 bird, with which (as Mr. Gray has suggested to me) Sir Andrew Smith's subse- 

 quently designated Querquidula hottentotta (Zool. S. Afr. Axes, pi. 105) seems to 

 be identical; and the Australian bird will take up with its next synonym — 

 standing then as Anas castanea (Eyton). 



