Diversity of chemosymbiotic bivalves on coral reefs: Lucinidae (Mollusca, Bivalvia) of New Caledonia and Lifou Author Glover, Emily A. Author Taylor, John D. Department of Zoology, The Natural History Museum, London SW 7 5 BD (United Kingdom) emily. glover @ dial. pipex. com j. taylor @ nhm. ac. uk taylor@nhm.ac.uk text Zoosystema 2007 29 1 109 181 journal article 10.5281/zenodo.5392295 1638-9387 5392295 Myrtina leptolira n. sp. ( Figs 6C ; 8 ) TYPE MATERIAL. — Holotype : 1 RV, L 16.4 mm , H 14.8 mm , T 3.6 mm ( MNHN ). Paratypes :from type locality, 1 LV, L 14 mm , H 13.8 mm ; 1 LV, L 14.3 mm , H 12.6 mm ; 1 LV, L 14.3 mm , H 12.7 mm ; 1 LV (damaged), L 9.7 mm , H 8.7 mm ( MNHN ); 1 RV, L 15.6 mm , H 14.9 mm ( BMNH 20050570). TYPE LOCALITY. — Loyalty Islands , stn DW 442, 20°54’S , 167°17’E , 200 m . ETYMOLOGY. — Latin lepto , thin, lira , ridge MATERIAL EXAMINED. — New Caledonia . MUSORSTOM 4, stn DW 150, 19°07’S , 163°22’E , 110 m , 1 v. Loyalty Islands . MUSORSTOM 6, stn 441, 20°54’S , 167°17’E , 80 m , 1 v. — Lifou, stn 1461, 20°54’S , 167°08’E , 100-120 m , 1 v. DESCRIPTION Small to medium sized,H to 14.9 mm , L to 16.5 mm , subcircular (H/L 0.90-0.99), posterior margin truncate. Sculpture of fine, closely spaced, regular, thin, commarginal lamellae with occasional radial threads. Lamellae more elevated in anterior and posterior dorsal areas.Antero-dorsal area demarcated by slight sulcus. Lunule long, lanceolate, smooth, slightly asymmetrical, slightly larger in left valve. Ligament long, external. Hinge plate narrow; right valve with single bifid cardinal tooth, a short anterior lateral tooth and posterior lateral absent; left valve with two cardinal teeth, the anterior larger, posterior thin; lateral teeth absent. Anterior adductor muscle scar long, detached from pallial line for 1/4 of length. Posterior adductor scar oval to reniform. Pallial line sometimes discontinuous.Shell interior glossy, radial threads within pallial line, tracks of adductor scars often white ( Fig. 8G ); shell margin smooth FIG. 7. — Myrtina porcata n. gen., n. sp. : A , B , holotype (MNHN), secteur de Poindimié, New Caledonia, interior and exterior of right valve; C , paratype (MNHN), exterior of left valve; D , paratype (MNHN), exterior of left valve; E , protoconch; F , detail of sculpture; G , H , paratypes (MNHN), interior of left and right valves; I , J , paratypes (BMNH 20050569), details of hinges of left and right valves; K , paratype (BMNH 20050569), dorsal view of lunule. Scale bars: A-D, I, J, 5 mm; E, 100 µm; F, K, 500 µm; G, H, 2 mm. FIG. 8. — Myrtina leptolira n. gen., n. sp. : A , B , holotype (MNHN), Loyalty Ridge, stn DW 442, New Caledonia, interior and exterior of right valve; C , detail of sculpture; D , E , paratype (MNHN), interior and exterior of right valve; F , G , paratype (MNHN), interior and exterior of right valve; H , paratype (BMNH 20050570), exterior of left valve; I , J , detail of hinge teeth of left and right valves. Scale bars: A, B, D-H, 5 mm; C, 500 µm; I, J, 2 mm. REMARKS Myrtina leptolira n. sp. differs from M. porcata n. sp. in the more closely spaced and lower commarginal lamellae that are less extended dorsally, and in the more circular shell outline.