260 COLUMBA PALUMBUS. 



The bill is of moderate length, rather slender, straight ; the 

 tumid basal membrane irregularly granulated, the dorsal out- 

 line of the upper mandible to\Yards the end arcuato-declinate, 

 the sides convex, the edges straight and soft for two-thirds of 

 their length, then decurved, direct, horny, the tip obtuse and 

 edged ; the lower mandible svith the angle long, narrow and 

 rounded, the dorsal outline slightly convex, the edges sharp 

 and decurved towards the tip, wdiich is rather acute. 



Both mandibles are internally concave, the upper with a 

 central ridge. The palate is flattened in the central space, and 

 externally of the two soft diverging ridges slopes upwards. 

 Parallel to the anterior slit, which is papillate on the margins, 

 on each side is a single series of small papillae. The oesopha- 

 gus, which is seven inches and a quarter long, measured from 

 the base of the tongue to the stomach, dilates immediately, and 

 continues enlarging, until it is suddenly expanded into a mem- 

 branous sac, or crop, two inches and a quarter in length, three 

 inches and a quarter in breadth, and lying across the neck and fore 

 part of the thorax. On entering the latter, the oesophagus gra- 

 dually contracts to half an inch. The transverse muscular fibres 

 are conspicuous, the inner coat smooth until at the lower aper- 

 ture of the crop, when it is raised into seven longitudinal rugae, 

 three inches long, converging downwards, and terminating near 

 the proventriculus. These rugae are covered with mucous 

 crypts. The proventriculus is one inch long ; its glands ovate 

 and large. The gizzard is an inch and three-fourths in length, 

 an inch and a half in breadth, and three-fourths in thickness. 

 Its muscular coat is composed of two thick lateral muscles, a 

 lower thin muscle over the fundus, and a series of circular 

 fibres at the upper part. The middle coat, which is continuous 

 with the inner membrane of the oesophagus, is thick and tough. 

 The inner or cuticular coat is marked with regular longitudinal 

 rugae on the transversely elliptical spaces opposite the thickest 

 parts of the muscles. 



The pylorus is situated in a fissure between a small bulging 

 and the upper edge of the right muscle, and is destitute of any 

 valvular apparatus. The intestine is six feet six inches long. 

 The first fold incloses the pancreas as usual, which is two inches 



