This marble bas-relief is called Thetis Rising from the Sea, by Thomas Banks (1735-1805) in London's Victoria and Albert Museum. My students like this one a lot. It is pretty easy to see what is going on here, and is pretty easy to describe.
Then Achilles gave a loud cry and his mother heard him as she was sitting in the depths of the sea by the old man her father, whereon she screamed, and all the goddesses daughters of Nereus that dwelt at the bottom of the sea, came gathering round her. There were Glauce, Thalia and Cymodoce, Nesaia, Speo, Thoe and dark-eyed Halie, Cymothoe, Actaea and Limnorea, Melite, Iaera, Amphithoe and Agave, Doto and Proto, Pherusa and Dynamene, Dexamene, Amphinome and Callianeira, Doris, Panope, and the famous sea-nymph Galatea, Nemertes, Apseudes and Callianassa. There were also Clymene, Ianeira and Ianassa, Maera, Oreithuia and Amatheia of the lovely locks, with other Nereids who dwell in the depths of the sea. The crystal cave was filled with their multitude and they all beat their breasts while Thetis led them in their lament. (Iliad, 18, Butler)In class I'm always calling attention to the visual qualities of Homer's poetry, but its compelling aural poetry is effective even in English prose. Here Homer prefigures Thetis leading the lament for her son, who hasn't actually died yet. It's like a rehearsal.