Recently I've been reading 永田カビ's 一人交換日記, and have come upon the word 通目 there, used in every "chapter" heading. Judging from context, I think this word would mean something like "entry", but I haven't been able to find it in the standard dictionaries (広辞苑 and the 国語大辞典 have it listed, but the meanings listed there are completely unrelated).
How is 通目 read? What does it mean?