Serdica in Thracia, 253-268 AD., Gallienus, 3 Assaria, Ruzicka 489.

Serdica in Thracia, Gallienus, 253-268 AD.,
Æ 3 Assaria (27-29 mm / 17,78 g),
Obv.: AV[T K ΓAΛ] - ΛHNOC , radiate, draped bust of Gallienus with spear and shield left, seen from behind.
Rev.: OVΛΠI - AC - CЄPΔIKH / [C] , crouching Artemis, taking a bath, accompanied with two attendant nymphs, the left nymph dressing the goddess's hair.
Ruzicka, Die Münzen von Serdika, Numismatische Zeitschrift, vol. 48, 1915, pp. 1, ff., pls. I-IX. This coin is p. 76, no. 489 .

http://www.forumancientcoins.com/board/index.php?topic=47269.0 ; http://en.wikipedia.org/wiki/Crouching_Venus .

Thanks to Patricia Lawrence for digging out the complete reference and discussing the mythological possibilities of the reverse scene.