Taxonomy of tropical West African bivalves. VI. Remarks on Lucinidae (Mollusca, Bivalvia), with description of six new genera and eight new species Author Cosel, Rudo von Muséum national d’Histoire naturelle, Département Systématique et Évolution, Unité Taxonomie et Collections, case postale 51, 57 rue Cuvier, F- 75231 Paris cedex 05 (France) cosel @ mnhn. fr cosel@mnhn.fr text Zoosystema 2006 28 4 805 851 journal article 6343 10.5281/zenodo.4689802 cb4d8e3b-abd4-4a73-b074-8dd9ab59f5a6 1638-9387 4689802 Genus Joellina n. gen. TYPE AND ONLY SPECIES. — Joellina dosiniformis n. sp. DISTRIBUTION. — Off Ambrizete, northern Angola , tropical West Africa. DIAGNOSIS. — Shells medium-sized, subcircular, slightly oblique towards posterior, hardly longer than high to almost as long as high, compressed, with a rather short and broad anterior part and a high, broad and oblique posterior part, without indentation. Anterior margin rounded and in its upper part slightly indented. Beaks well in front of the vertical midline. Umbones slightly prominent. Surface with irregular commarginal lamellae and growth lines. Antero-dorsal depression short and pronounced, postero-dorsal depression broad and illdefined. Lunule very short, narrow, asymmetrical and deeply sunken, escutcheon very narrow and completely filled by the ligament. Hinge plate very broad with long posterior part, with one very small and vestigial cardinal in the right valve and socket in the left valve; laterals small to indistinct. Ligament short and broad. Diverging part of anterior adductor scar long and broad, with a length of about 2/3 the total length of the scar. Inner margins smooth. TABLE 12. — Joellina dosiniformis n. gen., n. sp. : measurements (in mm) and length/height ratio.

Shell length × height (no tumidity)	Specimen	Length/height ratio
32.4 × 30.0	Angola, paratype (MNHN)	1.1
31.5 × 30.2	Angola, paratype (MNHN)	1.0
30.5 × 28.9	Angola, paratype (MNHN)	1.1
29.6 × 27.3	Angola, paratype (MNHN)	1.1
29.4 × 27.0	Angola, holotype (MNHN)	1.1
29.0 × 27.8	Angola, paratype (BMNH)	1.0

ETYMOLOGY. — Dedicated to my colleague Joëlle Galeron (IFREMER, Brest) in acknowledgement for her close collaboration on the deep-water mollusc fauna. REMARKS This new genus is most close to the fossil genus Pterolucina Chavan, 1942 , from the Upper Cretaceous to Tertiary (Miocene) ( type species Lucina coeloprocta Cossmann, 1887 , Upper Eocene of France ), there is no Recent lucinid genus with which it can be compared, however, according to the description and figure in Chavan (1969) , Pterolucina has more separated areas and a stronger hinge dentition.