Coliracemata, Ponder, Winston F., Fukuda, Hiroshi & Hallan, Anders, 2014

Ponder, Winston F., Fukuda, Hiroshi & Hallan, Anders, 2014, A review of the family Clenchiellidae (Mollusca: Caenogastropoda: Truncatelloidea), Zootaxa 3872 (2), pp. 101-153 : 130

Coliracemata n. gen.

Type species: Coliracemata mortoni n. sp.

Etymology. Colis (Latin): penis; racemus (Latin): bearing bunches or clusters of grapes. Gender feminine.

Diagnosis. Shell minute (less than 1.9 mm in diameter; Fig. 16 ). Spire flat except for raised protoconch, or slightly raised, periphery evenly convex; umbilicus moderate to wide. Whorls with many distinct, minutely wavy, spiral cords; spiral keels absent. Aperture near circular, peristome simple, prosocline, external varix absent. Operculum similar to Clenchiella with central peg but with triangular white, possibly calcareous, plate-like deposit covering muscle insertion area on middle of inner side. Head-foot colourless with no pigment; posterior end of foot rounded. Radula as for family, cusps on inner outer marginal teeth slightly larger than those on outer marginals. Penis with two or three clusters of many apocrine glands on dorsal edge of middle portion. Bursa copulatrix small to large; bursal duct short. Two seminal receptacles.

Remarks. Members of this genus are distinguished from Clenchiella in having evenly rounded shells (no keels; although spiral threads cover the shell surface as in Clenchiella ) which lack an apertural varix, no black pigment on the head-foot, rounded posterior end of the foot (instead of pointed) and massive glandular extensions from the penis that are composed of many small but distinct apocrine glands. The radula is very similar to those of species of Clenchiella but the operculum differs in having a white smear covering the muscle insertion area on its inner side.

Three species are confirmed as members of this genus as they are known anatomically. Two additional species with unknown anatomy are provisionally included here based on a general similarity in shell morphology. Specimens from a mangrove forest in Sembawang, Singapore were examined alive and are probably a member of this genus but the material is unavailable for description.

Figures

FIGURE 16. Holotypes of new species of Coliracemata n. gen. (from left towards right: dorsal, lateral and ventral view respectively). A – C, Coliracemata mortoni n. sp. (AMS C. 269811; shell diameter 1.82 mm); D – F, Coliracemata katurana n. sp. (AMS C. 445414; shell diameter 1.06 mm); G – I, Coliracemata clarkae n. sp. (AMS C. 462962; shell diameter 1.36 mm).