1 16 Dr. Latham'j EJfay on the Trachea or Windpipes -of Birds. 



bony rim is much ftronger than any other part of it, and is curved 

 backwards, taking into, its middle one of the bronchia. The other 

 fide con filts of a bony box, fwelling in the middle, and furrowed by 

 feverai tranfverfe bands : from this fprings the other bronchia. 



XX. ANAS FERINA— The Pochard. Tab. xiv. Fig. .5, 6. 



A. cinereo-undulata, capite brunneo, fafcia pe&orali crirTo uro- 



pygioque nigro. 

 Anas ferina, Linn. Syji. Nat. i. p. 203. — Ind. Orn. ii. p. 862. — 



Raii Syn. Av. p. 143. A. 10. — Brif. Orn. p. 384. pi. 35. f. 1. 

 Millouin,Ifo/] Oif. ix. p. 216. — PL En/. 803. 

 Der Rothhals, Befch. der Berl. Nat. Fr. iv. p. 602. t. xvii. f. 5, 6. 

 Poker, Pochard, Red-headed Wigeon, Gen Syn. vi. p. 523. — • 



Br. Zool. No. 284. — Will. Orn. p. 367. t. 72. 



The trachea of the Pochard, at fir ft fight, feems to be fimilar to that 

 of theScaup, but, on inveftigation, will be found to differ confiderably. 

 In the firfl place, it is full two inches fhorter; it is alfo of very nearly 

 the fame dimensions throughout, or narrowing very little at the 

 bottom. The drum- like labyrinth approaches greatly to that of 

 the Scaup in texture, but is more round on the upper fide ; it is how- 

 ever crofled by a fmall bony partition as in that bird— in both cafes, 

 as may be fuppofed, by way of ftrengthening the membrane which 

 covers the cavity. The bony box, of which the other portion of 

 the labyrinth confifts, is fcarcely elevated on this fide, and on the 

 other much lefs fo than is feen in the Scaup ; it likewife forms an ob- 

 ftlfe angle with the reft o{ the trachea, but in the Scaup it does not 

 deviate from a continuation of a ftraight line, although forming a 

 eonfiderable enlargement. 



XXI. ANAS 



