[5] In 1928 George Hudson followed Meyrick's placement discussing and illustrating this species in his 1928 publication The butterflies and moths of New Zealand.

[7] The lectotype specimen, collected by T. R. Oxley in Nelson, is held at the Natural History Museum, London.

Each segment furnished with a row of long, very stout, blackish-brown bristles and tufts of short whitish hairs near ventral surface.

Each segment furnished with a row of long, very stout, blackish-brown bristles and tufts of short whitish hairs near ventral surface.

[8]The larva prepares a large pad of silk on a support upon which the pupa is attached by the whole of its flattened ventral surface.

Colour uniform grass green; integument polished, slightly and irregularly striated, with a row of impressions on each side of abdominal segments; limbs very faintly sculptured; no hairs or bristles.

[9] P. furcatalis also has a brown streak down the dorsal side of its abdomen which is also a distinguishing feature.

[8][10] Larvae reared on P. crassicaule produce pupa strongly spotted with black.

[10] The larvae are slow moving and rest on the upper surface of the leaves of its food plants.