Ohhh, I found a description of the Yith homeworld I think. Here is a link to a reading of the story https://www.youtube.com/watch?v=i56YqscHs44

The description of the creatures in the vision begins at 28:00 and the description of them exactly matches that of THe Great Race in The Shadow out of time, but this is curious because in The Shadow out of Time it was stated that the bodies the Yith had in that story were not their original forms but one stolen from native Earthlings