ἀκτὴ μὲν ἥδε , implying the antithesis, τῷ δὲ ἔργῳ ἤδη ἐπιχειρητέον, which is virtually given by vv. 11 ff. For μέν thus deprived of its answering δέ by a change in the form of a long sentence, cp. 1199 ff.