Malandena Iredale, 1937

Hyman, Isabel T. & Ponder, Winston F., 2010, A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family 2462, Zootaxa 2462 (1), pp. 1-148 : 67

Malandena Iredale, 1937

Malandena Iredale, 1933: 56 [nom. nud.].

Malandena Iredale, 1937c: 7 . Type species Macrochlamys suturalis Odhner, 1917 (OD).

Description. External morphology: Shell of about 4.8 whorls, glossy, spire and apex slightly raised. Protoconch smooth; teleoconch sculptured with spiral grooves that become slightly raised spiral lirae. Whorl profile flattened above and rounded below evenly convex periphery. Internal walls of early whorls complete; umbilicus open, very narrow U-shape. Mantle laps of medium length, narrow, tapering to a fine point, not fused, uniform in colour. Right and left mantle lobes small, median lobe absent. Sole of foot and caudal apparatus as for family.

Mantle cavity: As for family. Mantle with faintly visible minor blood vessels, pigmentation of white spots.

Digestive system: Small oesophageal crop present.

Genital system: As for family. Carrefour embedded in albumen gland, talon free. Free oviduct short; capsular gland absent; oviduct internally with irregular longitudinal pilasters. Bursa copulatrix inserted on vagina, moderately long, more than half spermoviduct length; duct of bursa copulatrix wide, distinguishable from bursa copulatrix, internally with longitudinal pilasters. Vagina internally with longitudinal pilasters. Epiphallus enters penis through simple pore; penis internally smooth, longitudinal penis pilasters present, penial diverticulum absent. Penial sheath present, enclosing only penis; penis retractor muscle attached to epiphallus. Epiphallus internally with longitudinal pilasters. Epiphallic retractor caecum absent. Flagellum present; flagellum and distal part of epiphallus without internal cryptae and externally smooth and slender. Spermatophore not present in dissected material.

Radula: Relatively long and narrow. Central tooth with small ectocones; mesocone lanceolate, shorter than tooth base. Lateral and marginal tooth fields distinguishable. Lateral teeth with endocone absent; ectocone equal in size to those on central tooth; mesocone shorter than tooth base. Marginal teeth with endocones absent; ectocones approximately same length and breadth as mesocone, not subdivided into extra teeth.

Remarks. This genus was introduced by Iredale (1933, 1937c) for Macrochlamys suturalis Odhner, 1917 and placed in the family Macrochlamydidae (following Odhner 1917) due to its large caudal horn and mantle lobes. The group was moved to Sesarinae by Burch (1976), along with Nitor . The genitalia, radula and jaw of Macrochlamys suturalis were described and figured by Odhner (1917).

Malandena can be differentiated from all other helicarionid snails with a slender flagellum by its lack of an epiphallic caecum.