This note is to complement the earlier paper on the same subject (Canad. Math. Bull. 3 (1960), 41–57) in two points. The first part presents a simpler proof of the minimum property (cf. 1. c. section 3) of the orthogonal functions Ψv(x) (cf. 1. c. p. 46). In the second part we introduce another orthogonal system of sectionally linear functions χo(x), …, χn(x) which leads to a particularly simple interpolation formula. These functions appeared, mutatis mutandis, in the author's study on sectionally linear functions over an infinite range about which a report will be given elsewhere.