comprises _Laughers_, _Frill-backs_, _Nuns_, _Spots_, _and Swallows_ .-- They are all very like the common rock-pigeon, but have each some slight peculiarity.

The Laughers have a peculiar voice, supposed to resemble a laugh.

The Nuns are white, with the head, tail, and primary wing-feathers black or red.

The Spots are white, with the tail and a spot on the forehead red.

The Swallows are slender, white in colour, with the head and wings of some darker colour.
Besides these races and sub-races a number of other kinds have been described, and about one hundred and fifty varieties can be distinguished.