144 LAUGHING GULL. 



In winter the head is white, the feathers on its upper part and on the nape 

 more or less brownish-grey in their concealed part, that colour appearing in 

 slight patches here and there, and especially along the posterior margin of 

 the part that is coloured in summer, as well as on a small space before the 

 eye. The rosy tint of the breast disappears after the breeding season. In 

 other respects the plumage is as in summer. 



Young fully fledged. 



Bill, feet, inside of mouth, and edges of eyelids, olivaceous-brown. The 

 upper parts are brownish-grey, the feathers edged with paler; the hind part 

 of the back light bluish-grey; upper tail-coverts nearly white; tail pale 

 greyish-blue, with a broad band of brownish-black at the end, the extreme 

 tips narrowly edged with white, the outer margin of the lateral feathers of 

 the same colour. The first four primaries are destitute of white at the tip. 

 A smaller patch before the eye, two slight bands on the eyelids, and the 

 throat, greyish-white; the lower part of the neck brownish-grey, the rest of 

 the lower parts greyish-white, the sides darker, the axillars ash-grey, the 

 lower surface of the wing dusky-grey. 



In an adult male the tongue is 14 inches long, slender, tapering, emargi- 

 nate at the base, with minute papillae, the tip horny along the back. The 

 oesophagus is 6 A- inches long, 5 twelfths in diameter until it enters the tho- 

 rax, then dilates to 1 inch and 5 twelfths; its walls are extremely thin, its 

 inner coat longitudinally plaited. Proventriculus very short, the belt of 

 oblong glandules being only 7 twelfths in breadth. Stomach rather small, 

 oblong, 1^ inches long, 10 twelfths broad; its lateral muscles rather thick, 

 the tendons large; the inner coat thick, horny, and thrown into very promi- 

 nent longitudinal rugae, its upper margin abrupt, and manifestly not continu- 

 ous with the inner coat of the proventriculus, as some have supposed the 

 epithelium to be in all birds. In the stomach remains of fishes. Intestines 

 1 foot 9|- inches long, its general diameter i inch. Rectum 1^ inches; coeca 

 extremely small, 2\ twelfths long, \ twelfth in diameter. 



Trachea 5^ inches long; its rings 110, extremely thin and feeble; its 

 diameter at the top A\ twelfths, at the lower part Z\ twelfths. The lateral 

 muscles are scarcely perceptible, the sterno-tracheal very slender; the infe- 

 rior larynx small; the bronchi of moderate length and width, with 25 half- 

 rings. 



