Note 874 — Chapter III · THE COMMUNION OF GODS AND MEN.
Reading edition
So I understand the somewhat obscure sentence, εἰ μὲν γὰρ μεταξὺ τοῦ ὠμοπλάτου δύο ὑμένες ἐξ ἀμφοτέρων μερῶν τῆς ῥάχεως κ.τ.λ., conjecturing οἱ before μεταξὺ, where Codex Vindob. has corruptly εἰ.