Coleglabra, 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 : 146

Coleglabra n. gen.

Type species: Colegrabra nordaustralis n. sp. — Coleglabra misspelt

Etymology. Colis (Latin): penis; glabra (Latin): smooth, unadorned.

Gender feminine.

Diagnosis. Shell minute (up to 1.9 mm in diameter). Whorls with few dorsally distinct spiral cords and indistinct spirals on base; strong spiral keels absent. Aperture near circular, peristome simple, prosocline, external varix absent ( Figs 28 D–I and 29F–K). Operculum simple with no peg or white deposit on inner side. Head-foot colourless with no pigment. Penis long, slender, tapering, with no distinct swellings or glands; arising from right side of head behind right eye; tip pointed, with no distinct papilla. Bursa copulatrix large, about 1/2 behind posterior wall of mantle cavity; bursal duct extremely wide, forming large, round chamber at anterior part. One seminal receptacle.

Remarks. The shells of members of this genus are similar to that of Colenuda kessneri in having a few spiral threads on the dorsal surface of the shell and weaker spirals on the base, lacking spiral keels and in having a relatively narrow umbilicus and a low to moderate spire (flat to slightly sunken in Clenchiella and some species of Coliracemata ). The shell of Coleglabra differs most obviously from that of Colenuda in having a simple peristome, that of Colenuda having a wide, shallow excavation and in lacking any external varix.

As in Coliracemata , the head-foot is unpigmented but it is not in the other two genera. The penis, like that of Colenuda , lacks distinct lobes or glands and, like Colenuda , the operculum lacks a central projection. The shell resembles that of some species of Coliracemata in having a slightly raised spire, no varix and rather weak spiral sculpture. The spirals are slightly irregular but less obviously wavy than they are in most species of Coliracemata . The edge of the aperture, viewed dorsally, is straight in species of Coliracemata and convex in the two known species of Coleglabra .

Only the type species of Coleglabra is known anatomically. Another species is provisionally included in this genus based on its similar shell.

Figures

FIGURE 28. Holotypes of Colenuda n. gen. and Coleglabra n. gen. (from left towards right: dorsal, lateral and ventral view respectively). A – C, Colenuda kessneri n. sp. (NTM P. 53500; shell diameter 1.79 mm); D – F, Coleglabra nordaustralis n. sp. (NTM P. 53502; shell diameter 1.82 mm); G – I, Coleglabra sentaniensis (ZMA 1206; shell diameter 1.1 mm).