Shell small, conic, oval in outline, solid, rather thick-shelled, nearly smooth, glossy, sculptured only with fine, regularly spaced concentric growth-lines. Colour cream, on the outside often tinged with a brighter orange-brown to purple hue, and covered with small brown to green axially oriented stripes and white spots. Inside similarly coloured, but not as bright. Protoconch capuloid, smooth, white. Length. 4.5 mm; width 3.4 mm.

This species shows little variation, except in its shell colour. Many specimens are quite pale, probably because they have been dead for a long time. Live-collected specimens have not yet been observed. The species is common in outer bays, from depths of more than 20 metres, except for the panamese record, which is from just 12-13 meters.
Though obviously a close relative of P. pustulata, P. perfestiva n. sp. is readily separable from that species by the smaller, higher, smoother, and stronger shell. Patelloidea pustulata is always dull-white with rather pale reddish dots and bands - never orange or purple with dark brown dots. It has a clearly visible axial sculpture, whereas in P. perfestiva n. sp. the shell lacks axial sculpture or shows only very weak axially oriented undulations.

Type locality: Curacao, Vaersenbaai, 45m