Hey Phathead,
When I had this issue I lost about 20 ric total over 3 weeks and a second infection, they looked just like yours does in the picture. By that time it was to late for them to be saved. What I noticed is they only came out at night I have talked to a couple of ricordea collectors and aquaculturist that deal with ricordea and they told me that it is a protozoa in alot of the same as red bugs for SPS.
During the day light hours I found them to hide in the rock rubble that the ric is on and under the pedal foot of the ric in the sand. One of the tell tale signs I found was also the the edge of the ric would pull in and look as though it had gotten stung by another coral. The only way I found them was some of my brightest orange rics that were being eaten had these bright orange little dots around them. Come to find out that is the protozoa and they tend to take on the pigments of the rics they are eating. I was also told it seems they come from with in the ric as well and spew out the mouth and then infect other rics, I was told this by a person that deal with aquaculture ricordea. He also said that alot of times this problem comes up when people who sell aquaculture ricordea don't keep the wilds and aquaculture separated and there is cross contamination.......Here is what I found out that worked and saved the rest of the rics I had.....
I started to use saltwater dips w/ iodine that didn't work so forget about that. Use Ro/Di water with iodine and don't worry about getting it to ph or any of that stuff. Put them in a bowl let them sit for a minute or 2 and then take a turkey baster and blow on them vigorously with the turkey baster. They will slime up alot and that is natural for them to do because of the stress. This will only work on ones that are in the beginnings of the infection. If it gets to far along like in your pic throw them out as they will become prey and continue the infection and keep the protozoa alive that is left in your tank. I then instead of putting them back where they were I moved them up higher in the rocks away from where the infection and other rics were. I kept the healthy ones and the sick ones separated from each other in the tank. This seemed to work as the protozoa don't, from my observations have the ability to swim but crawl on the substrate. There were rics that were on rocks that were right next to the infected ones and they didn't get infected the only thing I could see is that they were to high away from the substrate for the protozoa to crawl up on......I dipped the ones I saved every other day for a week and still have them today. I also came down with a second infection about 3-4 weeks ago and caught it in time to save another 5 but lost another 5 rics to it because I didn't catch it in time to save them......In total I have lost about 20 ricordea over the 2 infections with this protozoa, so now I dip all ricordea except for yumas as they do not seem to be the target of the protozoa so it seems they are species specific in their destruction.
I got the infection from a shipment of rics from a wholesaler that deals in aquaculture ricordea. It seems from some that I have talked to that they are coming in on big rocks out of Haiti since most of the stuff collected here in U.S waters does not have a lot or any rock on them. Good luck with it make sure you dip every other day and keep them separated from the healthy ones.....I still collect them and will continue to collect them till my tank is full but now I know there is a predator out there that we have to watch for just like zoanthids and SPS......Like G.I. Joe says "Knowing is half the battle".