n. A very large ratite bird of the genus Struthio.n. Four species of ostriches are now recognized, the name Struthis camelus being restricted to the northern species that ranges into Arabia. S. molybdophanes is from Somaliland, and S. meridionalis or masaicus from Central Africa. The southern species, S. australis, is the one that has been partially domesticated and is kept in ostrich-farms for the sake of its feathers. The eggs of these species differ quite as much as do the birds themselves, that of S. camelus being quite smooth while the others are more or less deeply pitted.