Nodilittorina (Echinolittorina) Habe, 1956: 96–99 (type by original designation Litorina tuberculata Menke, 1828; cited as Echinolittiorina in error, p. 96).
Diagnosis: Shell aragonitic; nodulose, granulose, spirally striate or entirely smooth; if smooth or striate then usually with dark axial stripes or axially aligned series of dashes; eroded parietal area may be present, sometimes a small pseudumbilicus; aperture dark with pale spiral band at base (i.e. anterior end) and sometimes another posteriorly. Cephalic tentacles with 2–3 longitudinal black lines, all black, or with broad transverse band at base distal to eye. Operculum paucispiral. Penis with blade-shaped filament (rarely swollen); base usually bifurcate (not so if mamilliform gland absent); usually a single mamilliform gland (sometimes absent, rarely 2); glandular disc of subepithelial glandular tissue usually present; penial vas deferens an open groove or rarely a closed tube. Rod-pieces of paraspermatozoa usually long and straight (rarely small and irregular, or curved). In pallial oviduct egg groove makes a simple loop through albumen gland, straight path through capsule gland and jelly gland; copulatory bursa opens in anterior or posterior position within straight section of pallial oviduct. Spawn a biconvex pelagic capsule with cupola-shaped upper side sculptured by concentric rings, containing single egg; development planktotrophic. Outer marginal radular tooth with flange at inside and usually also at outside of base. Distribution worldwide tropical and warm temperate. (Modified from Reid 2007.)
Remarks: The taxonomic history of this genus has been summarized by Reid (2007). Since the molecular phylogeny of Echinolittorina species by Williams & Reid (2004) a revised analysis with addition of new sequences (including the new species described herein, making a complete analysis of all 60 known members worldwide) has been published (Williams & Duda 2008; Fig. 1). Monographs are available of the eastern Pacific species [Reid 2002b; as ‘ Nodilittorina ’, but Austrolittorina fernandezensis (Rosewater, 1970) and A. araucana (d’Orbigny, 1840) are now excluded (Williams et al. 2003)] and of the Indo-Pacific species (Reid 2007).