124 Dr. Larnam’s Effay on the Trachee or Windpipes of Birds. 
XXVII. MERGUS ALBELLUS—The Smew. Tab. xvi. Fig. 3; 4. 
M. crifta dependente, occipite nigro, corpore albo, dorfo tempori- 
bufque nigris. — 
Mergus Albellus, Liza. Sy/?. Nat. i. p. 209-—Ind. Orn. ii. p. 831. 
Rati Syn, Av. p. 135+ A. 3.—Brif: Orn. vi. p. 24.5. t. 24. f. i. 
Petit Harle huppé, La Piette, Buf Ou/. vill. p. 271. pl. 24.— 
Pl. Enl. 449. 
Die weifle Nonne, Be/ch. ie Berl. Nat. Fr. iv. p. 596. t. 18. f. 72. 
Die weiffe Tauchente, Beck#. Vog. Deut/ch. ii. p. 738. 
Smew or White Nun, Gen. Syn. vi. p. 425. —Br. Zool. No. 262.— 
Will. Orn. p. 255. t. 64. 
This beautiful bird is confiderably fmaller than the two laft de- 
{cribed, and the authors above referred to will point it out fhould any 
one be ignorant of the fpecies. The fize of the trachea is {malleft 
near the upper part, but enlarges as it approaches towards the 
middle; from whence to the bottom part it continues of nearly equal 
dimenfions, the texture confilting of bony rings, with fcarcely any 
cartilage appearing to intervene. At the bottom part is a bony 
cavity as in the others, but of a different form, being much fmaller 
in proportion, and differing in fhape, the greater expanfe being fron» 
fide to fide, whereas in the others it is almoft upwards and down- 
wards: on one fide is a round hole covered by a drum-like mem- 
brane, and on the oppofite an oval {mooth hollow bone uniting with 
it; from the bottom of thefe arife the bronchie. 
In this, as in the former, two fpecies have been created out of one, 
and owing precifely to the fame caufe; which is, that of the 
soung male having the female plumage for fome length of time after 
growing to fize. Ihave detected this fomeé time fince by the laby- 
I rinth 
a 
