POTAMIDIDAE, H. Adams & A. Adams, 1854

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 : 598-599

FAMILY POTAMIDIDAE CERITHIDEA SCALARIFORMIS (SAY, 1825)

Material examined

Atlantic Ocean: US: Florida: highway A1A, Big Starvation Cove , 27°33.02′N, 80°19.34′W ( USNM 1143351 ) .

Description

Marginal fold S-shaped ( Fig. 10A ), terminating at posterior tip of sorting area; oesophageal aperture at tip of marginal fold recurved segment; sorting area elongately triangular, with rounded posterior margin; anterior sorting area modified into prominent concave flap; left margin of sorting area with slight bulge posteriorly bordering flap; accessory marginal fold straight along sorting area left margin, curving and bifurcating around posterior end of sorting area; sorting area pad and crescentic pads lacking; glandular pad large, elongate, flattened with narrow stalk, extending far posterior to gastric shield; paired digestive gland ducts opening at left of glandular pad; crescentic ridge long, extending from near oesophageal aperture, past digestive gland ducts, curving around posterior end of glandular pad, fusing to side of pad slightly behind gastric shield, with distal tip curving slightly into caecum; shallow caecum present opposite three caecal folds; accessory pads lacking; U-shaped fold present below style sac aperture; style sac extremely long, extending into mantle roof; typhlosoles fusing short distance anteriorly from gastric chamber.

Remarks

Described by Houbrick (1984: 7) as possessing a sorting area, paired digestive gland ducts, prominent gastric shield, ‘pad-like’ ridge (= crescentic ridge) between the oesophageal aperture and digestive gland ducts, and a very long style sac that invades the mantle roof.

Figures

Figure 10. Midgut anatomy of Potamididae. A, Cerithidea scalariformis (USNM 1143351). B, Telescopium telescopium (USNM 828804). C, Terebralia semistriata (USNM 1083479). Note that a small accessory pad is present, but is not visible in this view. D, Tympanotonus fuscatus (USNM 858078). Scale bars: 1.0 mm; refer to the text for a list of anatomical abbreviations.