Antoninus Pius, Alexandria, Egypt.
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     Antoninus Pius, Æ drachm, (25.21g) Alexandria, Egypt, Year 21 =
     157/8 AD, Laureate and draped bust right. / No legend. Isis, the
     Egyptian goddess and consort of Serapis, riding facing on a dog
     (Sirius) wearing a radiate crown running to right, LKA below.
     Sirius, the Dog star, is connected with summer heat and drought.
     Astrological type. Milne 2358, D2680, BMC1121.