Afrolittorina Williams, Reid & Littlewood, 2003

Reid, DG & Williams, ST, 2004, The Subfamily Littorininae (Gastropoda: Littorinidae) in the Temperate Southern Hemisphere: The Genera Nodilittorina, Austrolittorina and Afrolittorina, Records of the Australian Museum 56, pp. 75-122 : 100

Afrolittorina Williams, Reid & Littlewood, 2003

Type species. Litorina africana Krauss , in Philippi, 1847.

Taxonomic history. Both Afrolittorina africana and A. knysnaensis were classified by Rosewater (1970) as members of his new subgenus Littorina (Austrolittorina) , on the basis of their non-nodulose shells and Nodilittorina - like penes and radulae. The two remaining members, A. praetermissa and A. acutispira were transferred to L. ( Austrolittorina ) subsequently (Ponder & Rosewater, 1979). These four species were included in Nodilittorina (Austrolittorina) by Reid (2002 a), as defined by the loop of the egg groove through the capsule gland of the pallial oviduct. A formal cladistic analysis of morphological characters of Nodilittorina s.l. ( Reid, 2002 b) did not support Austrolittorina as a monophyletic group. However, it did identify these four species as a clade, supported by the single unequivocal and unreversed synapomorphy of the loop of the egg groove through the jelly gland (elsewhere in the subfamily this feature is found only in Melarhaphe neritoides , in which the loop is elaborated into a spiral). DNA-sequence data have since shown unequivocally that the four species are not members of the Austrolittorina clade, but are the sister group of the northern-hemisphere genus Littorina , thus justifying the introduction of the new genus Afrolittorina ( Williams et al., 2003) .

Diagnosis. Shell not nodulose; spiral striae or smooth; eroded parietal area usually absent; no pseudoumbilicus; pale with diffuse pattern of mottling, marbling or tessellation, rarely axially aligned. Cephalic tentacles with transverse lines, 1–2 longitudinal black stripes, or black.

Penis with swollen filament; base bifurcate; single mamilliform gland; glandular disc of subepithelial glandular tissue may be large, minute or absent; if absent, epithelium around mamilliform gland is tall and secretory; penial vas deferens an open groove. Rod bodies of paraspermatozoa long and straight, or small and irregular. In pallial oviduct egg groove makes a simple loop through albumen gland, large circular loop through capsule gland, smaller loop in jelly gland; copulatory bursa opens in posterior position. (After Williams et al., 2003.)