inscribed in purple ink on reverse u.c.: Hammerhead Series: Blue on blue / green incribed in fibre-tipped pen on reverse u.c.: (original title Sep 1965) artist stamp in purple ink on reverse u.c.: SIR GEORGE F. POLLOCK, BT., F.R.P.S., / THE WESTCOTT ART CENTRE, / 5 MAIN ROAD, WESTCOTT, / NR. DORKING, SURREY, / DORKING 4361 inscribed in fibre-tipped pen on reverse l.l.: "Underwater" by / George F. Pollock (underlined)
