4 
, 
5 
Dr. Latuam’s Effay on the Trachece or Windpipes of Birds. 109 
pear as divided into two unequal portions; on the oppofite part, or 
that fituated next.the breaft, itis flattened, and from the vba part 
of it the two dronchia have their origin. 
I have fome reafon for affirming, that authors have thahiesTacily 
divided the Teals into more fpecies than really exift; for the Tea/ fo 
called, andthe Summer Teal, certainly conftitute but one; and _ al- 
though ma/es have been met with of the latter, it is probable that 
the external diftinétion of feather may not be fixed till the fecond 
year, or even beyond that period: it is not. enough that the fe/fes 
are vifible; for, as above mentioned, that circumftance of itfelf can- 
only prove the /év: it is to. the labyrinth alone that we muft have . 
recourfe in all birds which poffefs it; for this remains nearly the 
fame during life. I fcarcely need here obferve, that the ma/e alone 
poffeffes. the labyrinth, not only in this, but alfo in every other 
{pecies | of Duck hitherto examined. 
XI. ‘ANAS CLYPEATA—The Seu Hee. Tab. xii. Figs 4. Se 
"A. roftri extremo tiated rotundato, ungue incurvo. | 
Anas clypeata, Linn. Sy/t. Nat.i. p. 200.—Ind. Ora. ut. p. 856.— 
“Raii Syn. p. 144. A.Q. ef 13.—Brif Orn, vi. p. 329. ts 32, f. I. 
Le Souchet, Buf. Of ix. p. 191.—P/. Enl. 971. 972. 
Die Loffelente, Schr. der Berl. Nat. Fr. iii. p. 373. t- 7. f. 2. 
Shovéler, Gen. Syn. vi. p. 509.—Br. Zod. ii. No. 280. 
This bird is about two inches longer than the laft, and is far 
from being uncommon. The end of the /rachea is furnifhed with a 
labyrinth, which is {mall in propor tion to the fize of the bird, 
being fcarcely more than half the fize of that of the Garganey. It 
is of nearly equal dimenfions. throughout, except near the bottom, 
where it flightly enlarges; on the left fide is a kind of bony blad- 
der a little irregular in fhape, about the fize of a large rounceval pea, 
with two or three flight indentations on the fides ;—from this fprings 
one 
