I realised as I was working on this that the slinkers aren't described as having three eyes - I thought that the Martian species was, but when I checked Valley of Dreams it turned out that I was wrong; there's a three-eyed Martian species seen only by the gleam of its eyes in darkness, but the eyes of the Martian slinker look-alike aren't described at all. So I'll have to alter that bit of the Mars section, and edit one image, but it's no big deal.
Later Apparently I spotted it much earlier and changed it then - damned if I can remember doing so...
