This specimen was collected by Rebecca (Becky) Lash who reports "I was looking at all the beroe when a blob that I thought was a dead mnemiopsis started flapping its little flappers. Don’t know what it’s been eating but it’s digestive tract seems full" It was brought to the MBL where we placed it into a tank to take photos. I recognized it as a pteropod and did a GBIF search for the group. None of the species seemed to fit. I posted on the Falmouth Wildlife Facebook group and a member referenced an article on "Sea Angels" I looked up the source and found a reference to Cliopsis krohnii, the only member of this genus. Looks much more of a match than Clione limacina. Going with that. Have video.