Parmavitrina disposita (Iredale, 1941) comb. nov.
Helicarion dispositus: Smith, 1992: 233.
Material examined. Probable holotype. AM C.101147 (Barrington Tops, NSW, 32°01’30” S, 151° 27’00” E, pre-1941; Fig. 22C).
Non-type material. See Table S1.
Diagnosis. Shell. Large, 3.7-4.4 whorls, amber, ear-shaped, flattened, protoconch slightly raised, last whorl large; shell glossy, protoconch with fine spiral grooves, teleoconch with very fine, indistinct spiral grooves (Table 3, Figs 22C, 23E).
Animal. Orange-brown with orange-red mucus, paler on sides of neck and along tail; sole cream, slime network well-developed, tail keeled, caudal horn small. Mantle lobes moderately large, none fused, median lobe forming small cephalic shield; shell lappets moderately large, connected by a narrow collar, right lappet rounded.
Genitalia. Bursa copulatrix short, approximately equal in length to free oviduct, sac spherical. Penis large, slightly swollen at proximal end, enclosed in penial tunica, penis interior with numerous longitudinal pilasters, becoming more irregularly shaped at proximal end with longitudinal threads between them. Epiphallus very short, less than penis length, swollen with internal cryptae; enters penis through a short verge. Epiphallic flagellum with spiraling rows of internal cryptae and slender tail. Spermatophore with branching spines on base of capsule and tail-pipe, tail-pipe very short, one very long, slender spine with no accessory branches attached near the junction of capsule and tail-pipe; spermatophore golden brown, tips of branches dark brown (Fig. 28).
Parmavitrina disposita can be distinguished from P. planilabris, which is similar in size, by its orange-brown body colour and complete shell. Its genital morphology differs from that of its congeners by the presence of a very short epiphallus and a large penis with a small verge and numerous longitudinal pilasters.