COMMON, OR WHITE-BACKED EIDER. 149 



thirds, then narrows to an inch ; its walls very thick, the 

 inner coat longitudinally plicate ; the proventricular part an 

 inch and a quarter in breadth. The stomach, an extremely 

 large and muscular gizzard, situated obliquely, two inches 

 and a half in length, three inches in breadth, the muscles an 

 inch and a quarter in thickness ; the epithelium thick, dense, 

 with two elliptical grinding plates. The intestine is six feet 

 four inches long, half an inch in width, enlarging a little 

 toward the coeca, which are three inches and three-fourths 

 long, only one-twelfth wide at the base, their greatest width 

 four-twelfths, narrowed to two-twelfths at the end, which is 

 obtuse ; the rectum four inches long, gradually enlarging to 

 ten-twelfths. 



The trachea, nine inches long, is nearly uniformly five- 

 twelfths in breadth, with a transversely oblong dilatation at 

 the lower end, projecting more to the left side, an inch in 

 breadth, and half an inch in length. The bronchi are very 

 wide, of moderate length, and with about thirty rings. 



The nostrils are large, oblongo-elliptical, five-and-a-half- 

 twelfths long, sub-medial, nearer the ridge than the margin. 

 The eyes small, as are the apertures of the ears. Legs very 

 short, stout, placed rather far behind ; a very small part of 

 the tibia bare ; tarsus compressed, with eighteen medial and 

 ten outer scutella, the rest reticulated. Hind toe small, with 

 a broad lobiform membrane connected at the base with the 

 loose bilobate membrane of the second toe ; the anterior toes 

 long, the outer about equal, the third with thirty-two scu- 

 tella, and double the length of the tarsus ; interdigital mem- 

 branes emarginate and denticulate. The claws are small, 

 compressed, blunt, arcuate, that of the hind toe more curved 

 and slender, of the middle toe curved outwards, internally 

 expanded and rounded. 



The plumage is rather short and dense. The feathers of 

 the head short, soft, blended, rounded, with the terminal 

 filaments disunited ; the occipital, and upper posterior and 

 lateral cervical, are rather long, stiff, linear, and terminated 

 by a pencil of disunited stiffish filaments, with silky lustre ; 

 feathers of the neck and breast softish, blended, and rounded ; 

 of the upi^er parts obovate, and rather distinct. The wings 



