A fine male killed at Boston, 34 inches in length, with an alar extent of 56, presents the following characters. There is a general layer of subcutaneous adipose tissue, and the skin is very tenacious. The external aperture of the ear roundish, very small, having a diameter of only 2 lines. The tongue is 2 inches 1 line in length, fleshy, as high as broad, slightly concave and longitudinally grooved above, tapering to a horny point. On the palate are 6 rows of papillæ; the posterior aperture of the nares is linear 2-1/2 inches in length. The aperture of the glottis is 1/2 an inch long, with numerous papillæ along its sides and behind. The pharynx is extremely dilatable, as is the œsophagus, which is 17 inches long, passes along the right side of the neck, together with the trachea, and when distended has an average diameter of 2-1/2 inches, but on entering the thorax contracts to 1-1/2. The structure of the œsophagus in birds may be very conveniently examined in this species, the different layers being remarkably developed in it. Properly speaking, it has only two coats,—the outer muscular, its external layer composed of transverse or circular fibres, the internal of equally distinct longitudinal fibres, which are not straight, but irregularly undulated. The inner, or mucous coat, when contracted falls into longitudinal plaits. The proventriculus is 2-3/4 inches long, the glandules large, roundish, simple, and disposed in a continuous belt. Over this part, the transverse muscular fibres are remarkably developed. The right lobe of the liver is 5-3/4 inches long, the left lobe 5-1/2. The heart is very large, of a broadly conical form, 3 inches long, 2-3/4 inches in breadth. The stomach is three inches long, 2-1/2 in breadth, of an elliptical form, a little compressed; its lateral muscles 9 lines in thickness, and composed of strong large fasciculi; the tendons 1-1/2 inch in diameter; the cuticular lining thick, its upper and lower parts marked with strong longitudinal ridges having numerous transverse fissures; the grinding surfaces irregularly wrinkled, with a deep fissure down the middle of each. The pylorus is 8 lines in diameter when distended, and is destitute of valve, but has a strong prominent rim. In the stomach were remains of fishes, and some pebbles, chiefly quartz, the largest 4 lines long. The intestine measures 6 feet 6 inches in length, and varies in diameter from 8 to 6 lines. The rectum is 3-1/2 inches long, the cloaca extremely large, forming a cavity about 3 inches in diameter. The cæca are 1-3/4 inch long, cylindrical, rounded at the extremity; one of them 7 lines, the other 9 lines, in diameter.