576 CRIBRATORES. SIFTERS. 



tough skin, attached to which is a considerable layer of adi- 

 pose tissue ; the head oblong, compressed. The bill never 

 very long, and sometimes short, is always covered with soft 

 skin, and furnished with internal marginal lamellae. The 

 tongue is fleshy, papillate at the base, medially grooved, late- 

 rally ciliated or furnished with reversed bristles, and having 

 a flattened, thin, roundish tip. The oesophagus is narrow, 

 without crop, but sometimes considerably dilated at the lower 

 part of the neck. The stomach is always an extremely mus- 

 cular gizzard, with a dense epithelium, having two grinding 

 plates. The intestine is long, and rather wide, with two long 

 and moderately wide coeca ; the rectum cylindrical. The 

 trachea in the female is uniform, of moderate bony rings ; but 

 in the males are diversiform enlargements at its lower extre- 

 mity. The contractor muscles, which are very large, give off 

 two slips, which are attached to the clavicle, and end in two 

 others, which go to the sternum, there being no inferior 

 laryngeal muscles. 



The skin is covered with a fine close elastic down. The 

 feathers are of moderate size, ovate or oblong, curved, with 

 the basal filaments very downy, and a downy plumule of con- 

 siderable length ; the feathers of the head and neck very 

 small, slender, in the male blended and glossy. The quills 

 are strong, and the tail feathers generally firm. 



All the species form a regular, though not generally 

 neatly constructed nest. The eggs are always numerous, 

 nearly elliptical, smooth, and of a uniform light tint, white, 

 or light greenish or cream-colour. The young, clothed with 

 thick stifnsh down, run, swim, and dive from the first. I 

 know of no other general characters. Those peculiar to the 

 different groups will be given in order. 



The Cribratores, among the swimming birds, are appa- 

 rently analogous to the Rasores among the Land Birds, and 

 have generally been considered as such. Next to the Galli- 

 naceous Birds they are those which are most directly useful 

 to man. To this series belong some of our most important 

 domesticated species : the Common Goose, the Duck, the 

 Swan, and several others of less value. Their feathers, supe- 

 rior to those of other birds in elasticity and softness, afford 



