... or so that's what the "Boss" say it is, and it's supposed to be one of the parent plants for Rhynchostylus Gigantea.
I have had this plant for many years now and it's one of my more faithful bloomers bringing out two spikes at a time every year.
I believe I found your orchid on OrchidWiz, please note the spelling: Arachnostylis Jittima. This is a hybrid of Arachnostylis Chorchalood x Rhynchostylis gigantea (which is a species orchid). In turn, the parents of Arachnostylis Chorchalood are Arachnis hookeriana x Rhynchostylis gigantea.
Therefore, Rhynchostylis gigantea is both a parent and grandparent to your orchid. Such beautiful blooms; thanks for sharing!