Planaxis sulcatus, (BORN, 1780)

Strong, Ellen E., 2011, More than a gut feeling: utility of midgut anatomy in phylogeny of the Cerithioidea (Mollusca: Caenogastropoda), Zoological Journal of the Linnean Society 162 (3), pp. 585-630 : 598

PLANAXIS SULCATUS (BORN, 1780)

Material examined

South Pacific Ocean : Australia: QLD: Lizard Island, South Island, 14°42.1′S, 145°27.4′E ( USNM 1083482 ) .

Description

Marginal fold thin, modified S-shape ( Fig. 9B ), terminating at posterior tip of sorting area; oesophageal aperture at tip of marginal fold recurved segment; sorting area triangular, with pointed posterior tip; left margin of sorting area with slight bulge; accessory marginal fold straight along left margin of sorting area, extending almost to posterior end of gastric chamber along midline of roof; sorting area pad, anterior flap, and crescentic pads lacking; glandular pad narrow, elongate, supported by narrow stalk, extending far posterior to gastric shield; single digestive gland duct opening at left of glandular pad; accessory pads, crescentic ridge, caecum, caecal folds, and U-shaped fold lacking; typhlosoles unfused.

Remarks

Previously described by Houbrick (1987a: fig. 2B), highlighting the narrow, elongate glandular pad with median groove, single digestive gland duct, and unfused typhlosoles. Details of the sorting area and accessory marginal fold were not elaborated.

Figures

Figure 9. Midgut anatomy of Planaxidae. A, Fossarus ambiguus (USNM 857631). Scale bar: 0.5 mm. B, Planaxis sulcatus (USNM 1083482). Scale bar: 1.0 mm. Refer to the text for a list of anatomical abbreviations.