[Rib duplication].

Fluorographic examination under roentgenographic control of 400,000 persons revealed rib doubling to be the rarest anomaly--3 cases (approximately, one case per 133,000 examined) and semi-doubling ribs--2 cases (1:200,000); in literature only one case of the right third rib doubling (P. V. Yashunin, 1936) is described. Our cases of rib doubling are: the third, left; the fourth, left and the only case of neighbouring ribs doubling--the first and second, left; semi-doubling: the third, left (demonstrated) and the fifth, left.