Progress report on the SLD cerenkov ring imaging detector

We describe test beam results from a prototype cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider (SLC). The system includes both liquid and gas radiators, a long drift box containing gaseous TMAE and a proportional wire chamber with charge division readout. Measurements of the multiplicity and detection resolution of cerenkov photons, from both radiators are presented. Various design aspects of a new engineering prototype, currently under construction, are discussed and recent R&D results relevant to this effort are reported.