The small birds commonly called Stormy Petrels or Mother Carey's Chickens, of which the Atlantic Procellaria pelagica is the best known, have been divided into several genera, the present being one. In it the bill is slight and shorter than the head, the orifice of the combined nostrils single; wings very long, with the 2nd quill longest; the tail moderate, the outer rectrices slightly longer than the middle pair; tibia partly nude, tarsi smooth, not scutellated, much longer than the toes ; the hind toe only represented by a minute claw; basal phalanx of middle toe not flattened and shorter than the other phalanges and the claw together ; claws sharp, spatulate, but little flattened.
This genus ranges throughout the Southern Oceans and into the North Temperate zone. Two species are known, of which one is probably the common small Petrel of the Indian seas.
* ' Challenger' Reports, Zool. iv, pt. xi, p. 1. Classification of Birds, p. 34 ; Suppl. p. 15. Cat. 23. M. XXV, p. 342.