The concept of the interval, to the extent that it exists only negatively, through an absence, makes it possible to explore genealogy of media and intermediality from a new perspective, and more particularly, in the present case, to examine our understanding of cinema with respect to the many and shifting ways it takes its place in the media environment. To that end, the present article proposes to examine the concept of the interval from the perspective of the concept of the cultural series. The institution, as an agent for defining the identity of each medium, and thus as the guarantor of a medium’s “ID card,” often acts as the manager of the identity intervals which separate and distinguish media. In this way the movie theatre, the view of some, provides a decisive identity interval for distinguishing cinema from other ways of apprehending images in motion. For our part, we will argue in favour of a serial reading which calls for the fixed aspect of these institutionalised intervals separating media to be transcended and for the cartography of media intervals to be revised and re-organised – not hesitating, in the process, to re-interpret or modify them or to create new ones for the legitimate needs of research.