When the speaker of the poem refers to the greek goddesses, lethe and phyche, in “ode on melancholy,” he is using the literary device of ? apostrophe allusion metaphor personification

The answer is:

Allusion

The literary device allusion is when the writer directly or indirectly refers to something that is commonly known or famous in which the subject matter is being described as, so that the reader will have a clearer picture of the writer’s description. In Lythe, the allusion was “Underworld” while in Psyche, the allusion used was “Cupid”.