Diphyoropa Hyman & Stanisic, 2005

Shea, M., Colgan, D. J. & Stanisic, J., 2012, 3585, Zootaxa 3585, pp. 1-109 : 33-36

Diphyoropa Hyman & Stanisic, 2005

Stanisic et al. 2010: 224.

Type species. Helix saturni Cox, 1864 —original designation.

Diagnosis. Shell very small, coppery brown with evenly coiled whorls and flat spire. Protoconch sculpture bimodal with the first two thirds of the protoconch having broad, irregularly spaced spiral cords that weaken on the last third where broad, curved radial ridges develop and eventually dominate. Teleoconch sculpture of prominent, almost straight, widely to closely spaced radial ribs and cancellate microsculpture. Umbilicus wide to very wide Vshaped. Kidney weakly bi-lobed. Epiphallus long. Penis tubular, sculptured with longitudinal pilasters.

Distribution and habitat. Southern outskirts of Sydney (Woronora River) mid-eastern NSW northward to the Macleay Valley, northern NSW and into south-eastern Qld; living in dry vine thicket, eucalypt woodland and forest, or suburban gardens and even wasteland where it has been found on undersides of logs, wood, rocks and dumped rubbish.

Remarks. Distinguished by the bi-modal protoconch sculpture that consists of low fairly widely spaced spiral cords with low radial ripples developing on the last third, planispiral shell shape, flat spire, orthocline teleoconch ribs, wide V-shaped umbilicus, rounded whorls and coppery brown coloured shells. The protoconch sculpture is structurally similar to that of Cumberlandica , however, the elements in the case of Diphyoropa are low, broad spiral cords and low radial ridges. These are fundamental differences in the architecture of the sculpture which are considered to be the basis for generic separation between these two sympatric groups.

Undescribed taxa with similar shell features (specifically protoconch sculpture) fitting the general concept of the genus occur sporadically northward along the coast and tablelands into south-eastern Qld. Stanisic et al. (2010) describe D. jonesi from south-eastern Queensland but whether or not this and the other northern NSW species truly belong to this genus has yet to be confirmed by anatomical or molecular studies except that a specimen of NN23 with a Diphyoropa -like protoconch from Iluka (AMSC.463582) belongs to the genus according to ITS-2 analyses ( Fig. 5).