Potadoma, Swainson, 1840

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 : 608

POTADOMA CF. FREETHI (GRAY, 1831)

Material examined

Africa: Cameroon ( MRAC 796831).

Description

Marginal fold extending along right margin of sorting area, terminating at posterior tip ( Fig. 14B ); configuration of proximal marginal fold not visible; oesophagus opening anteriorly to left side of gastric chamber, separated from style sac aperture by major typhlosole; expanded proximal tip of major typhlosole forming large vertical septum, anteriorly subdividing gastric chamber; sorting area highly curving, broad anteriorly, tapering rapidly to blunt tip; left margin of sorting area with conspicuous bulge; paired crescent-shaped pads bordering left margin of sorting area; inner crescentic pad narrow, rounded with thick, even ribbing across surface; outer crescentic pad narrow, flattened, with fine, weak transverse striae across surface; accessory marginal fold extending posteriorly from near tip of outer crescentic pad, flaring around posterior margin of sorting area, continuing to posterior end of gastric chamber; sorting area pad lacking; proximal glandular pad low, broad, coarsely ridged, extending short distance past gastric shield; distal glandular pad modified into series of branched leaflets; foliate structure extending posteriorly from tip of proximal glandular pad; single digestive gland duct opening at left of glandular pad; crescentic ridge long, extending from digestive gland duct, curving around foliate structure, separated by broad, shallow crescentic groove, joining distal tip of foliate structure well behind gastric shield; accessory pads, caecum, and caecal folds lacking; U-shaped fold present below style sac aperture; typhlosoles unfused.

Figures

Figure 14. Midgut anatomy of Pachychilidae. A, Tylomelania abendanoni (MNHN). B, Tylomelania palicolarum (MNHN). Scale bars: 1.0 mm; refer to the text for a list of anatomical abbreviations.