Viviparous. Bearing young alive.
Warp. The deposit of muddy waters.
Wealden. The name given to an important fresh-water formation, occurring between the Cretaceous and Oolitic rocks, chiefly in the Wealds of Kent and Sussex.
Whin-stone. A provincial term applied to some trap rocks.
Zamia. A plant allied to the palm, plentiful east of the Cape of Good Hope.
Zeolite. A group of minerals which swell and boil up when exposed to the blow-pipe flame.
Zoophyte. The term applied to some animals of low organization, which, during the greater part of their lives, are attached to some foreign substance, and are incapable of locomotion.