CIMRM 87 - Research note by Vermaseren on the Sidon Mithraeum.
See also: CIMRM 74 Mithraeum; 75 Tauroctony relief; 76 Tauroctony statuette; 77 Mithras carrying bull statuette; 78-9 lion-headed statuette; 80 Cautes statuette; 81 Cautopates statuette; 82 Cautes with axe statuette; 83 Cautes with axe statuette; 84-5 Hecate statuette; 86 Two Venus statuettes; 87 Vermaseren's research note;
This entry appears to be a place-holder for material which, in the end, Vermaseren was unable to develop.
I.e. "in a chamber without windows, entirely walled-up (in order to escape destruction)."