Mesoginella translucida (Sowerby, 1846)
Diagnosis: Shell small to medium, white or yellowish white, occasionally with pale yellow band below suture on body whorl; not strongly narrowed anteriorly; spire medium height; aperture moderately narrow; lip smooth, moderately thickened internally, thickest centrally; external varix present; siphonal notch present; posterior notch well defined; weak ventral callus on some specimens; columella with four strong plaits occupying about half of aperture length, 4th fold remote.
Size: Adults 5-8 mm in length.
relatively tall spire and yellow subsutural band, when present, distinguishes this species within the genus.
It is quite variable in shape, as shown in fig. 1.
Some specimens are similar in outline to Austroginella johnstoni but may be separated by the different lip
Synonymy: Marginella volutiformis Reeve, 1865 and Marginella attenuata Weinkauff, 1879 are synonyms. Laseron described a large specimen as Marginella humerica Laseron, 1948 (Hewish in Wilson, 1994); although unusually large for the species, it falls within the range of variation.
Remarks: This species appears to be unusual among Australian marginellids in having a short range, almost restricted to NSW.
Fig. 1: Middle Harbour, Sydney (C.032413)
Fig. 2a: North Harbour, Sydney (C.316227); this is the specimen illustrated by Laseron (1948, fig. 16)
Fig. 2b: HOLOTYPE of Marginella humerica Laseron, 1948; off Tacking Point, Port Macquarie, in 12 fathoms (22 m) (C.103365)
Copyright Des Beechey 2003