Innesoconcha rosacea, (IREDALE, 1944)

Hyman, Isabel T., Caiza, Jennifer & Köhler, Frank, 2023, Dissecting an island radiation: systematic revision of endemic land snails on Lord Howe Island (Gastropoda: Stylommatophora: Microcystidae), Zoological Journal of the Linnean Society 197, pp. 20-75 : 69-70

INNESOCONCHA ROSACEA ( IREDALE, 1944)

( FIGS 5K–O, 6J, 22G–I, 25, 26; TABLE 1)

Tribocystis rosacea Iredale, 1944: 323 , pl. 20, fig. 7. Melloconcha rosacea Smith, 1992: 238 ; Stanisic et al., 2010: 346–347; Hyman & Köhler, 2020: 112. Tribocystis alma Iredale, 1944: 324 . Melloconcha alma Smith, 1992: 237 .

Type material: Holotype, AM C.38940 ( Fig. 5K), near The Pines (31°32.08′S, 159°4.14′E), 1912, R.Bell.

Holotype of Tribocystis alma, AM C. 63477 ( Fig. 5L), North Ridge , between North Bay & Hunter Bay (31°31.06′S, 159°2.97′E), 1905, R.Bell.

Material examined: See Table 1.

Description

External morphology: Shell ( Fig. 5K–O) small ( SW 3.7–4.1 mm, SH 1.7–2.2 mm), 4.8–5.2 whorls, highly glossy, slippery, orange-brown to reddish brown, discoidal with a flat or slightly raised spire. Protoconch and teleoconch sculptured with fine microspiral grooves. Whorl profile rounded above and below a rounded periphery, sutures flat. Animal ( Fig. 6J) grey, with darker grey eyestalks and tail tip. Right shell lappet long, narrow, finger-shaped, left shell lappet absent.

Pallial caƲity: Pigmentation absent; mantle gland present.

ReproductiƲe system ( Fig. 25): Oviduct with six eggs, one to three embryos. Penis short, not coiled; epiphallus enters penis through a simple pore or small verge (present in one specimen); penis internally flat, one to two longitudinal penis pilasters present; apical diverticulum on penis present. Penial tunica enclosing penis (not coiled) and epiphallus. Epiphallus shorter than penis, internally without sculpture.

Radula ( Fig. 22G–I): Marginal teeth with ectocones slightly shorter and narrower than mesocone, multicuspidate. Radular formula (18.4.1.4.18) × 69.