The Ionic headword -- here only with this accentuation (contrast pi 2263) -- is glossed as a nominative plural and must presumably, therefore, be accepted as such (rather than being neuter nominative singular of a two-ending neuter adjective; see generally LSJ s.v. pranh/s, -e/s., and cf. pi 2548).
[1] See already at pi 2548. [In her critical apparatus Adler reports that ms G transmits the later variant spelling pronenohko/tes.]
[2] From an epitaph for a dolphin, Greek Anthology 7.214.7-8 (Archias); Gow and Page, vol. I, pp. 414-5. The headland of Cape Malea is the tip of the eastern peninsula extending south from the Peloponnese (Barrington Atlas map 57 grid B5); cf. mu 100. Adler reports that mss GM replace ga\r (for) with ga/rgaron: as high as Gargaron, a wave by the headland of Malea. Gargaron is the crest of Mount Ida, in the Troad, present-day Turkey (Barrington Atlas map 57 grid E2).
Adler also notes that in the margin ms M inserts o)rqo/teron gra/fein ou(/tws: h)= ga\r i)/son p. M. o(\ e)kukh/qh kai\ ta\ e(ch=s: better to write thus: for truly as high as the headland of Malea, there stirred up...and so forth.
The awkward translation "sand-laden...beaches" attempts to preserve a problematic redundancy in the original Greek: poluya/mmous (many-sanded) and yama/qous (sandy shores); for attempted emendations, see Gow and Page, vol. II, pp. 445-6.