Plesiotrochus unicinctus, (A. ADAMS, 1853)

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 : 590

PLESIOTROCHUS UNICINCTUS (A. ADAMS, 1853)

Material examined

South Pacific Ocean : Australia: QLD: Lizard Island, Mermaid Cove, 14°38.9′S, 145°27.3′E ( USNM 1083784 ) .

Description

Oesophagus ( Fig. 2E ) opening broadly to anterior end of gastric chamber at left; epithelium of gastric chamber roof and floor finely grooved, with several prominent transverse ridges; gastric shield small, weakly concave, along right wall of gastric chamber opposite oesophageal aperture; gastric shield continuous with cuticular lining of gastric chamber roof; sorting area extending between gastric shield and oesophageal aperture to elevated shallow shelf in front of style sac aperture; crystalline style pocket lacking; glandular pad lacking; two digestive gland ducts present; posterior duct opening mid-ventrally to gastric chamber floor; anterior duct opening to sorting area near anterior end of gastric shield; typhlosoles unfused; crystalline style lacking.

Remarks

Overall, the organization of the midgut is rather simple, and lacks the hallmarks of basal microher-

Figures

Figure 2. Midgut anatomy of Plesiotrochidae. Plesiotrochus unicinctus (USNM 1083784). Scale bar: 0.5 mm; refer to the text for a list of anatomical abbreviations.