THE GREAT BLACK-BACKED GULL. 
66 
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 larger 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-J 
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 proven tricular glands, which are very small, being 1-J twelfths in length, 
and 4 twelfth broad, form a belt 14 inches in breadth, traversed by very 
prominent rugae, 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 4 i 
twelfths ; the cceca inch long, 4 inch wide, their distance from the extre- 
mity 5 inches, the rectum is 8 twelfths in width, and the cloaca forms a 
globular dilatation 1-J- inches in diameter. 
The trachea is 12 inches long ; at the top 7 h twelfths wide, gradually con- 
tracting to 44 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 
