It does not matter, Aquagility. Either will be accepted. Where there is more than one recognised spelling for an answer, each will be accepted - this has been confirmed by the Telegraph's Crossword Editor, Kate Fassett.
Thank you all. I will bow to Jools' arithmetic and go for griffin.
JD, it's because Kate almost always manages to slip one in - and there's never a cross clue to give a firm answer. she's her father's daughter, that one.
Quite correct JD .. this relates to the Saturday Telegraph GK crossword, which for many years was set by Michael Mepham until his untimely death a few months ago.
His daughter Kate Mepham has since admirably taken over the reins to continue providing this interesting and challenging puzzle!