Contributions to Zoology, 86 (1) – 2017Isabel T Hyman; Irantzu de la Iglesia Lamborena; Frank Köhler: Molecular phylogenetics and systematic revision of the south-eastern Australian Helicarionidae (Gastropoda, Stylommatophora)

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Brevisentis Hyman, 2007

Brevisentis Hyman, 2007: 93.

Type species: Helix jacksoniensis Gray, 1834, by original designation; masculine


Diagnosis. Shell. Medium-sized, discoidal to depressedly globose with low spire; whorls rounded; protoconch with fine, shallow spiral grooves, teleoconch with spiral rows of very fine pustules; umbilicus narrow (Fig. 7-8).

Animal. Grey to black with red mucus in at least two species. Mantle lobes moderately small; shell lappets elongate, triangular (Fig. 9).

Genitalia. Ovotestis of 4-5 lobes embedded in digestive gland. Talon usually embedded in digestive gland. Spermoviduct not folded. Distal portion of free oviduct with elongate capsular gland; free oviduct internally smooth. Bursa copulatrix relatively long, reaching half to two thirds of the way along spermoviduct, inserted on vagina, internally with longitudinal pilasters in duct; sac oval to tear-shaped. Vagina short, internally with longitudinal pilasters. Epiphallus enters penis through verge; epiphallic caecum absent; epiphallic flagellum with axial filament present, containing small internal cryptae. Spermatophore is a soft-walled capsule with hard tail-pipe, with short branching spines in spiraling pattern on tail-pipe.

Remarks. Brevisentis originally contained two species that were previously included in Melocystis Iredale, 1937, a genus now considered as a synonym of Nitor Gude, 1911 (Hyman, 2007). A third species, B. kaputarensis, was subsequently included for strong similarity in shell features (Stanisic et al., 2010). The monophyly of Brevisentis as so delineated is confirmed herein. The three allopatric species have very similar shells, but differ in body colouration and genital anatomy. Samples from Wollemi National Park, Great Dividing Range, do not group with any described Brevisentis species in mtDNA phylogeny but form the sister group of (B. atratus + B. kaputarensis), probably representing an undescribed species. However, because the single lot consists of immature specimens only, we delay description of this species pending collection of suitable material.