Heads are those of Cupid and Psyche, inscribed "To Apollo" (6)

I believe the answer is:

capita

'heads' is the definition.
('heads' in Latin)

I cannot understand how the remainder of the clue works.

(Other definitions for capita that I've seen before include "Per ..., per head" , "'Per ..., for each person (6)'" .)

I've seen this clue in the Independent.

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