252 THE RAZOR-BILLED AUK.. 



glossed with olive-green, the throat and sides of the neck tinged with 

 chocolate, the wings with brown, the tips of the secondary quills, and a 

 narrow line from the bill to the eye, white. 



Length to the end of tail 17 inches, to the end of claws 17f ; extent of 

 wings 29^; wing from flexure Si; tail 4; bill along the ridge 1 T 7 2, along the 

 edge 2-Y2, its greatest depth ||; tarsus 1 T 2 2; middle toe 1 T 8 2, its claw T 5 2- 

 Weight 1^ pounds. 



Adult Female in summer. 



The female is precisely similar to the male. 



The Young in their winter plumage have the colouring distributed as in 

 the old birds, but with the black duller, the wings more brown, the throat 

 and sides of the head mottled with white, the white line from the bill to the 

 eye existing, but the bill much smaller, without furrows or a white line. 



The Old Birds in winter have the throat and sides of the neck mottled as 

 described above; but in other respects their colours are the same as in 

 summer. 



The gullet wide, dilated towards the lower extremity, its mucous coat 

 longitudinally corrugated; the proventriculus very wide and glandular; the 

 stomach rather small, oblong, muscular, with an inner, longitudinally cor- 

 rugated and horny cuticular coat. Pylorus very small; intestine near its 

 commencement jj of an inch in diameter, gradually contracted to the coeca, 

 where it is T y, coeca half an inch long, tapering. The length of the gullet 

 and stomach together is 8, that of the intestines 41 inches. 



On the palate are several series of reversed papillae, and two longitudinal 

 papillate ridges; on its anterior part are five prominent lines; the posterior 

 aperture of the nares linear, 1 inch in length; width of mouth 11 twelfths. 

 Tongue li inches long, fleshy, slender in its whole length, trigonal, fiat 

 above, with a median groove, and tapering to a very thin horny point. 

 CEsophagus Sj inches long, its width along the neck 10 twelfths, but within 

 the thorax it forms an enormous sac 3|- inches long, 1 inch 11 twelfths in 

 breadth; the proventricular glands ver} r numerous, forming a complete belt 

 3i inches in length, and occupying almost the whole of the sac above 

 mentioned. Stomach very small, 10 twelfths long, 9 twelfths in breadth; 

 its muscular coat thin, the tendons round, and about 5 twelfths in breadth; 

 the epithelium thin, dense, and longitudinally rugous. Intestine 53 inches 

 long, its average width 5 twelfths; the coeca 9 twelfths long, l| twelfths in 

 breadth, 2 inches 1 twelfth distant from the extremity; cloaca globular, and 

 about 1 inch in diameter. 



Trachea 5 inches long, from 4±- twelfths to 3 twelfths in width, a little 

 flattened; its rings 95, unossified. Bronchi very wide, of IS half rings. 

 Cleido-tracheal muscles, lateral muscles, sterno-tracheal slips, and a single 

 pair of inferior laryngeal muscles. 



