Atys multistriatus Schepman, 1913

Atys multistriata Schepman, 1913: 468, pl. 32, fig. 2.

Atys multistriatus — Carlson & Hoff 2000: 170. Gosliner et al. 2008: 23.

Type locality. Balabalagan Islands, between Borneo and Sulawesi ( Paternoster Islands)

Material examined. Mariana Islands, Guam, 2 spcs dissected, UF 374136, H = 6.27 mm, 6.6 mm .

Animal (Fig. 1D): Body whitish-translucent, white dots scattered all over body, red dots and white blotches on mantle; eyes visible.

Shell (Figs 2E, 9A, B): Maximum height 11.75 mm; whitish; fragile, thin, semi-translucent, elongated, oval, with slightly convex sides, anterior end protruded, posterior end truncated; spire sunken, outer lip elevated slightly above the apex, aperture narrow posteriorly and broader anteriorly, columella short, slightly concave, with a fold at the base; spiral grooves throughout shell but weaken in middle part, conspicuous axial lines present, creating netlike pattern all over the shell but weaken in middle part.

Jaws: Elongated with multiple denticles (Carlson & Hoff 2000).

Radula: Radular formula at mid-point 21–23 x 5–4.1.4–5; median tooth broad, slightly bilobed, with weak denticulation and small lateral cusp; outer lateral teeth hook-shaped, with weak denticulation (Carlson & Hoff 2000). There is no differentiation between inner and outer lateral teeth.

Gizzard plates (Figs 9C–E): Three gizzard plates; broader at anterior part, narrower towards posterior end; 20 ridges, thick, become crescent-shaped towards both ends, middle ridges inverted V-shaped, ridges covered by single rows of tiny rods with pointed tips along top edge, both anterior and posterior sides of ridges smooth.

Male reproductive system (Fig. 9F): Total length 3 mm (H = 6.27 mm). Formed by three parts: prostate, seminal duct and penial region; prostate single-lobed, ovoid, translucent; long seminal duct connects the prostate to penial region, about four times the length of prostate, opaque-yellow; penial region cylindrical-elongated, about half of the length of seminal duct, slightly broader than seminal duct, semi-translucent.

Ecology. Shallow water, reef flat to 21 m depth on sandy bottom (Carlson & Hoff 2000; Gosliner et al. 2008).

Geographical distribution. Indonesia, the Philippines, Guam, Palau, Hawaii, Tahiti, Fiji (Kay 1979; Carlson & Hoff 2000; present study).

Remarks. This species has a conspicuous reticulated sculpture on the shell, which is uncommon among haminoeids species. This feature can also be seen in Schepman’s (1913: pl. 32, fig. 2a, b) illustration of the holotype. Jaws and radula could not be successful prepared for SEM and descriptions are based on Carlson & Hoff (2000). According to the latter authors, this species possesses a bilobed median tooth with fine denticulation. This feature is known in the Mediterranean and eastern Atlantic species Atys macandrewii (Martinez & Ortea, 1998) and was found in the new species here described and named Atys pittmani . The shell of Atys multistriatus and its anatomy differs from the type species Atys naucum . The disparity of shell shapes and anatomies across Atys species hints that the genus may not be monophyletic. Preliminary molecular phylogenetic results (Too 2011) point in this direction, but a generic splitting of Atys will require the use of a broader taxon sampling; therefore, we refrain to do it at this stage.