198 ANATID^. 



the " Duck from the Sandwich Islands '' examined hy me show the- 

 following characters : — 



1. The rump and upper tail- coverts are black; also the under 

 tail-coverts are more or less black, but mixed with chestnut in 

 some specimens. 



2. The abdomen has a greyish tinge and traces of dusky narrow 

 cross bars. 



3. The head on the upper part is blackish, glossed with green, 

 while the sides and throat have dark streaks as in A. obscura ; in 

 one specimen the throat is blackish. 



4. The crop-region and breast are reddish chestnut, with black 

 markings more or less of a crescent shape, especially on the sides. 



5. The feathers of the mantle and interscapular region have 

 black and rufous-chestnut undulated bands, and many feathers, 

 especially on the side, are finely waved with grey. 



6. The speculum is glossy green, with a bluish lustre in some 

 specimens, and is bounded anteriorly by two bands on the last row 

 of the upper wing-coverts — one, subapical, whitish grey, and the 

 other, apical, black ; posteriorly the speculum is bounded also by two 

 bands — a subapical one, black, and a broad apical one, white. In 

 some specimens the anterior whitish band is almost obsolete. 



7. The tertials arc brown-grey, the outer ones have the outer 

 web velvety black. 



8. The upper wing-coverts are dark grey, with narrow rufescent 

 edges. 



9. The under wing-coverts are white, but in some specimens the 

 marginal ones are dusky. 



10. The size is smaller than in A. boscas ; total length about 

 18 inches, wing 9-25, culmen 1-85. 



11. Colour of the soft parts: bill black above, flesh-coloured 

 below ; feet orange. 



The female resembles that of A. boscas, but is smaller, darker, 

 and has the speculum green, the upper wing-coverts more or less 

 with rufescent edges ; the bill dusky, with a yellow band near the 

 tip. 



ITie young bird resembles the adult female, but has dark streaks 

 also on the throat ; the markings on the underparts are more like 

 longitudinal streaks. 



Young in doivn are very similar to the same stage of A. boscas, 

 but perhaps the brown colour of the upper parts is more olive. 

 (BoihscJiild Coll.) 



Hob. Sandwich Islands. 



a, b. S moult, et Ilawai (Knudsm). Prof. Collett [P.]. 



5 ad.sk. 



c. cJ juv.sk. Hilo, Owhyhee. Vov. of H.M.S. 



'Challengeiy 

 (Type of species.) 



d. S jun. sk. Hilo, Owhyhee. Vov. of H.M.S. 



' Challeno-er.' 



