Here is what I found:
"While feather stars usually react positively on the fine foods of Fauna Marin, Basket stars prefer much coarser foods. I had one for about a year and it just loved Mysis! Basket stars can easily be fed in the evening, just let some Mysis or Artemia drift into their arms, they will immediately curl up and stuff the food into their mouth, which is on the bottom of the star, facing towards the substrate. They do have an opening at the top, but this is the rear end. Several people tried to force feed them but just gave these poor critters an enema."