Adult specimens were selected for examination. Maturity was determined by ascertaining, through dissection, the whorl count at which specimens were found to have a mature reproductive system. Genital anatomy was examined through dissection of ethanol-preserved specimens using a Leica MZ8 stereo microscope with a drawing apparatus. Prior to dissection, the shell was removed and mounted on carbon tabs for scanning electron microscopy (SEM). Spermatophores were removed from the bursa copulatrix and cleaned by rinsing and the removal of extraneous tissue with fine forceps.
Shells were measured with calipers with a precision of 0.1 mm. Dimensions measured were height (H = maximum dimension parallel to axis of coiling), diameter (D = maximum dimension perpendicular to H), aperture height (AH = maximum dimension of aperture parallel to axis of coiling), aperture width (AW = maximum dimension of aperture perpendicular to H) and number of whorls (NW = whorl count using method shown by Köhler (2011)).
Analyses of covariance (ANOVA) of morphometric parameters were performed using XLStatistics (Rodney Carr 1997-2011, Deakin University).