ORCAS (Ὀρκάς, Ptol. 2.3.1), a promontory on the N. coast of Britannia Barbara, now Dunnet Head. It should be remarked, however, that Ptolemy (l.c.) places it on the E. coast, and gives it the additional name of Tarvedum (Ταρουιδούμ). [T.H.D]
Dictionary of Greek and Roman Geography, illustrated by numerous engravings on wood. William Smith, LLD. London. Walton and Maberly, Upper Gower Street and Ivy Lane, Paternoster Row; John Murray, Albemarle Street. 1854.