The subcutaneous cellular tissue is largely developed, and the longitudinal cells on the neck are extremely large, as in Gannets and Herons. The olfactory nerve is of moderate size, and the nasal cavity is a simple compressed sac 4 twelfths in its greatest diameter. The external nares are closed, and there are _no supraorbital glands_. The external aperture at the ear is circular, and not more than half a twelfth in diameter. The trachea is 13-1/2 inches long, much flattened, narrow at the upper extremity, where it is 2-1/2 twelfths in breadth, enlarging gradually to 4-1/2 twelfths, and toward the lower larynx contracting to 2-1/2 twelfths. The rings are very slender, unossified, and feeble; their number 230; the bronchial half-rings 25. The contractor muscles moderate; sterno-tracheales; and a pair of inferior muscles going to the last ring. In a young bird scarcely two days old, and measuring only 3-3/4 inches in length, the two most remarkable circumstances observed refer to the nostrils and stomach. The posterior or palatal aperture of the nares is of the same form, and proportional size, as in the adult; the nasal cavity is similar; but there is an external nasal aperture, or nostril, on each side, so small as merely to admit the mystachial bristle of a Common Squirrel. The stomach is of enormous size, occupying three-fourths of the cavity of the thorax and abdomen, being 10 twelfths of an inch long, and of an oval shape. The proventriculus is separated from the stomach and formed into a roundish lobe, as in the old bird; and beside it is the lobe or pouch appended to the stomach, and from which the duodenum comes off. Even at this very early age, the stomach was turgid with a pultaceous mass apparently composed of macerated fish, without any bones or other hard substances intermixed. Here then we have an instance of external nares in the young of a bird in which they are entirely obliterated in the adult. SURF DUCK. _FULIGULA PERSPICILLATA_, BONAP. PLATE CCCXVII. MALE AND FEMALE.