THE GREAT BLACK-BACKED GULL. 183 



brown, the feet as in the adult. The head and neck are greyish-white, 

 streaked with pale brownish-grey; the upper parts mottled with brownish- 

 black, brownish-grey, and dull white, the rump paler. The primary quills 

 blackish-brown, slightly tipped with brownish-white; the tail-feathers white, 

 with a large brownish-black patch towards the end, larger on the middle 

 feathers, which are also barred towards the base with dusky. The lower 

 parts are greyish-white, the sides and lower tail-coverts obscurely mottled 

 with greyish-brown. 



Male, from Dr. T. M. Brewer. The mouth is of moderate width, its 

 breadth being 1 inch 9 twelfths; the palate flat, with two very prominent 

 papillate ridges, and four series of intervening papillae; on the upper man- 

 dible beneath are five ridges, and the horny edges are prominent and thin, 

 but very strong; the posterior aperture of the nares linear, 1 inch 9 twelfths 

 long. The tongue is 2 inches 2 twelfths in length, fleshy above, horny 

 beneath, rather narrow, deeply channelled, the base emarginate and finely 

 papillate, the tip narrowly rounded. 



The left lobe of the liver is larger than the right, which, however, is 

 more elongated, being 4 inches in length, the other 3 inches; the gall-bladder 

 oblong, 1 inch 2 twelfths by 7 twelfths. There is a large accumulation of 

 fat under the parietes of the abdomen, and appended to the stomach. 



The oesophagus is 14 inches long; at the commencement its width is 2\ 

 inches, it then contracts to 1 inch 9 twelfths, at the lower part of the neck 

 enlarges to 2 inches, and towards the proventriculus to 2\ inches; it then 

 suddenly contracts at the commencement of the stomach. This organ is 

 rather small, and of an oblong form, 2^ inches long, 1 inch 9 twelfths broad; 

 the lateral muscles of moderate size, the inferior prominent, the tendons 

 large and radiated; the epithelium extremely dense, thick, with strong longi- 

 tudinal ridges, and of a bright red colour. It contains remains of crabs. 

 The proventricular glands, which are very small, being 1^ twelfths in length, 

 and \ twelfth broad, form a belt \% inches in breadth, traversed by very 

 prominent ruga?, continuous with those of the stomach. The inner mem- 

 brane of the oesophagus is strongly plaited, and that part is capable of being 

 distended to 3 inches. The intestine is 50 inches long, its greatest width A\ 

 twelfths; the cceca \ inch long, \ inch wide, their distance from the extremity 

 5 inches; the rectum is 8 twelfths in width, and the cloaca forms a globular 

 dilatation 1^ inches in diameter. 



The trachea is- 12 inches long; at the top 7J twelfths wide, gradually con- 

 tracting to 4^ twelfths, considerably flattened, its rings slightly ossified, 148 

 in number, of moderate breadth, very thin, contracted in the middle line 

 before and behind; the last half ring is large, moderately arched. In this, 

 as in all the other Gulls, there is a pair of slender muscles arising from the 



