Ever since Luo Zhenyu and Wang Guowei elucidated the appellations of the ancestors of the Yin royal lineage, thus confirming for its most part the authenticity of the Shang genealogy as recorded by Sima Qian in his殷本紀, scholars have endeavoured to match the names appearing on oracular bones with those of the royal ancestors recorded in the殷本紀, without paying attention to the authenticity of the sources of the史記. This paper attempts to prove that the sentence 「契卒, 子昭明立」 originates from the世本, whose own source is to be found in the sentence「契玄王, 生昭明」 of the 《荀子、成相篇》. It is shown that the latter sentence has been misread as meaning ”Qi gave birth to a son named Zhaoming”, while its original meaning should read「契是殷人玄王, 天生英明」 ie ”Qi was an ancestor of the Yin royal lineage, endowed with great virtues”, thus adding to the 殷本紀 a non existent royal ancestor..