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Cancer (the crab), one of the twelve signs of the Zodiac (see Zodiacus,) thus called from some similitude to the crab-fish: the sun entering that sign in the month of June, begins gradually to recede from us, and to take a retrograde course, as it were in crab like fashion. On a coin struck by M. Durminus, one of the moneyers of Augustus, is a crab, with a butterfly between its claws.
The figure of a Crab holding an aplustrum in its claws, there being under that shell-fish the rhodian rose, shows that the denarius of the Servilla gens, on which it appears, was struck at Rhodes.
This constellation immortalises the giant crab that attacked Heracles when he was trying to kill the Hydra at Lerna. The image is shown on a AE drachm of Antionious Pius minted at Alexandria.