186 Proceedings of the Royal Physical Society. 



to this, Dr Cunningham, who lately visited the straits as 

 naturalist on board H.INI.S. " I^assau," and who made a special 

 study of the Steamer duck, says, " The average length of the 

 adult bird may be stated as about thirty inches, and I do not 

 think that I ever met with specimens measuring more than 

 three feet from the unguis to the tip of the tail, so that I am 

 'inclined to believe that the specimen mentioned by King as 

 forty inches in length was of exceptional size." The museum 

 specimen is from King's collection, and agrees very closely with 

 his description both as regards colour, markings, and measure- 

 ment, witli the single exception of the length, which, instead 

 of forty, is exactly tliirty inches. This remarkable difference 

 of ten inches in the length, while the other measurements 

 agree, suggests the probability of some mistake — a slip of the 

 pen or a printer's error — by which forty may have been sub- 

 stituted for thirty, and of course this view would be put 

 beyond doubt if the museum specimen is the individual on 

 which King founded his Oidemia Patachonica. King further 

 describes what he considered a new species of duck under the 

 name Anas specularoides, and his description agrees in every 

 particular with the specimen which he presented to the 

 College Museum, and which was labelled by the late Pro- 

 fessor Jameson as the Anas spccularoides of King. In the 

 British Museum hand-list of birds, A. sjMcidaroides is given 

 as a synonym oiAnas chalcoptera, Kittl.; but if our specimen 

 be the actual individual described by King, it appears to me 

 to belong to the species A. cristata — a bird which, according to 

 Cunningham, is the duck most commonly met with in the 

 Magellan Straits, always excepting the Steamer duck already 

 referred to. The specimen has a slight crest, w^hich is not 

 mentioned in King's description, and which, from its insigni- 

 ficance, may have been overlooked by liim, and this crest is a 

 feature in the male of Anas cristata, Gm. I have not, how- 

 ever, been able to prociu^e either a figure or description of 

 Anas chalcoptera, of which A. sioecularoides is said, in the 

 British ^luseum hand-list, to be a synonym; but if my 

 surmise should, on further investigation, prove to be correct, 

 then King's name would become a synonym of A. cristata^ 

 Gm. 



