(Πιερίδες), and sometimes also in the singular, Pieris, a surname of the Muses, which they derived from Pieria, near Mount Olympus, where they were first worshipped among the Thracians (Hes. Th. 53; Hor. Carm. 4.3.13; Pind. P. 6.49). Some derived the name from an ancient king Pierus, who is said to have emigrated from Thrace into Boeotia, and established their worship at Thespiae. (Paus. 9.29.2; Eur. Med. 831; Pind. O. 11.100; Ov. Tr. 5.3. 10; Cic. De Nat. Deor. 3.21.)