Several sources prove that sheep lungs played an important role in Ancient Mesopotamian extispicy practice. Nevertheless, they have received comparatively little attention in Assyriology. The terminology used by ancient diviners to describe the various parts of the divinatory lung represents an especially neglected area of research. This article represents a new attempt at resolving some of the problems created by the ancient terminology. It demonstrates how different types of sources associated with the divinatory inspection of the lungs give us clues to identify many previously unidentified parts of the divinatory lung. In particular, the article offers a new edition of the Neo-Assyrian lung model Rm 620 and discusses the identification of two, so far elusive, parts of the divinatory lung, imēr ḫašî “the Saw-horse of the lung,” and muštašnintu “the Leveller.”