Trochomorpha (Hartmanitrochus) rubens Hartman 1888

Figures 11M, 33I, 38D, 41B, 42A–C

Material examined. Vanuatu: FMNH 175247 (two specimens dissected, one radula examined), 3–11 km S of Hog Harbour, plateau top, NE Espiritu Santo, alt. 120 m, 29–30 Oct. 1972, L. Price.

Description. External morphology: Shell of about 6.2 whorls, light orange-brown, glossy, spire and apex raised. Protoconch smooth; teleoconch sculptured with strong radial growth lines. Whorl profile rounded above and below keeled periphery. Internal walls of early whorls complete; umbilicus open, narrow U-shape. Animal light orange-brown. Mantle laps and lobes absent. Sole of foot undivided; caudal apparatus with sole longer than foot (Muratov’s 1999 zonitid type).

Mantle cavity (Figure 38D): As for family. Pigmentation of black and white spots, mantle gland absent.

Digestive system: Oesophageal crop absent.

Genital system (Figures 33I, 41B): As for family. Carrefour and talon both not embedded in albumen gland. Free oviduct long; capsular gland present; internal longitudinal pilasters absent. Bursa copulatrix inserted at junction of penis and free oviduct, short, less than half spermoviduct length; duct of bursa copulatrix wide, distinguishable from bursa copulatrix, internally with longitudinal pilasters. Vagina absent. Penis moderately long; epiphallus enters penis through simple pore; penis internally smooth, three major longitudinal penis pilasters present (additional pilasters at base), penial diverticulum absent. Penial sheath absent; penis retractor muscle attached to junction of penis and epiphallus. Epiphallus shorter than penis, internally with longitudinal pilasters. Epiphallic retractor caecum absent; Flagellum and lime-sac absent. Spermatophore not present in dissected specimen.

Radula (Figure 42A–C): Relatively long and narrow. Central tooth with no ectocones; mesocone triangular, much longer than tooth base. Lateral and marginal tooth fields distinguishable. Lateral teeth with endocone absent; ectocone much smaller than those on central tooth; mesocone much longer than tooth base. Marginal teeth with endocones absent; ectocones slightly shorter and narrower than the mesocone, not subdivided into extra teeth. Radular formula (33.13.1.13.33) × 109 rows.

Remarks. The anatomy of Trochomorpha rubens is figured by Schileyko (2002a), and agrees with that described above except for the presence of a few additional short pilasters around the base of the penis interior that were seen in the current study but are absent from Schileyko’s (2002a) figure.

The subgeneric arrangement of Schileyko (2002a) is followed in the current study. The subgenus Hartmanitrochus is limited to Vanuatu and the Malaku Islands, and contains two to three species (Schileyko 2002a).

Trochomorpha rubens grouped with Videna planorbis (Trochomorphidae) in the phylogenetic analysis (Figures 1–3). In the molecular phylogenetic analysis of Wade et al. (2006), the genera Trochomorpha and Videna also grouped together (Figure 44B).