I think that the symbol on the left may mean patrol. It shares components with the modern Chinese character xún 廵. In ideographic terms, it is the symbol for travel quickly (to run), with the addition of an extra person: perhaps the idea of a rapid response team. The drawings below are of two examples from Isturitz.
The example on the right is of particular interest, because it also features the character èr 二, which can mean disloyal or treacherous.
Reading from top to bottom, and right to left, we have:
Treachery; treachery; block; patrol
Irregular timescale: 3; 10; 8; 9; 10; 7
It is difficult to tell from the tracing which marks were natural and which marks were man-made. Also, I don’t have the context, so I don’t know what they may have been patrolling or what the time units were. However, the idea of a patrol at random intervals is clear.
Patrol symbol: Drawing: Lynn Fawcett, October 2013
Tracings of lissoirs: René de Saint-Périer, 1930: La grotte d’Isturiz, Tome I: Le Magdalénien de la salle Saint-Martin: Archives de l’Institut de Paléontologie Humaine, mémoire 7: Masson et Cie, Paris: Source: Examples of others compositions on smoothing tools and assimilated pieces from Magdalenian of Isturitz and Laugerie-Basse: Claire Lucas, 2011: Gravures sur côtes: Engraving on rib bones : graphic combinations in Middle Magdalenian from Isturitz (Pyrénées-Atlantiques): Figure 10: Paleo, Revue d’Archéologie Préhistorique, numéro 22, p. 189-206 : http://paleo.revues.org/docannexe/image/2128/img-10.jpg: Accessed 28 October 2013