Shells of most species in this group superficially resemble those of Pterynotus species in having three winged varices per whorl. However, in Pteropurpura the operculum and radula show-affinities to those of Ocenebra; moreover, the siphonal canals are fused, as in Ocenebra. With one exception (P. bequaerti), all species of the group inhabit the North Pacific. Some species show little variability in shell form or color throughout their range. In a few species, however, a marked color range is apparent in specimens from different regions. Surface sculpture may also range from almost smooth to richly imbricate. At times these sculptural differences may coincide with divergences in shell proportion. No correlation has been shown as yet between these differences, on the one hand, and latitudinal distribution, water depth, or other ecological parameters, on the other.