Fig. 8. Fields of view of the left set of secondary eyes of Drassodes cupreus. The fields are plotted onto a globe with the spider at the centre. The pole of the grid is straight up, and the one-ended arrow marks the longitudinal axis of the spider. The two-ended arrows indicate the direction of polarization to which each of the three eyes is most sensitive. Note the large and almost circular field of view of the posterio-median eye. AL, anterio-lateral; PL, posterio-lateral; PM, posterio-median.