Determine the rhyme scheme of the following poem.

XII (From Fairie Queene, Book I, Canto 11)
But stings and sharpest steele did far exceed
The sharpnesse of his cruell rending clawes;
Dead was it sure, as sure as death in deed,
What ever thing does touch his ravenous pawes,
Or what within his reach he ever drawes.
But his most hideous head my toung to tell
Does tremble: for his deepe devouring jawes
Wide gaped, like the griesly mouth of hell,
Through which into his darke abisse all ravin fell.