In T.S. Eliot's "The Love Song of J. Alfred Prufrock," what figures of speech are used in lines 57-58 and 73-74?

In "The Love Song of J. Alfred Prufrock," T.S. Eliot uses a variety of figures of speech, especially metaphors. A metaphor is a comparison that does not use the words "like" or "as." Two examples of metaphors are seen in lines 57 - 58 and 73 - 74.  In the first of these, the persona of the poem compares himself to a specimen being mounted for scientific study. It could be a butterfly, insect, or other such creature that is being called to mind. The metaphor is made more graphic by showing that the persona is being mounted while he is still alive, for he is "pinned and wriggling on the wall." In the second, the persona compares himself to a crab or other such creature that scuttles along the ocean floor. Both these metaphors speak to the insignificance that the persona feels when confronted not only with social situations, which he finds awkward, but also with the great questions of life, such as the meaning of existence and whether there is an afterlife.