Catalogue and bibliography of Recent and fossil Botula (Bivalvia: Mytilidae) Author Kleemann, Karl text Zootaxa 2007 1508 1 48 journal article 10.5281/zenodo.177199 e7464a80-067d-41b3-91eb-fcfd3f3b8f5c 1175-5326 177199 Lithophaga Röding, 1798 ( Fig. 1 ) Type species. L. mytuloides Röding, 1798 , by monotypy, referring to Gmelin’s (1791: 3351) species 6, Mytilus lithophagus Linnaeus, 1758 . Diagnosis. Shell cylindrical, posteriorly more compressed, with vertical striae antero-ventrally and lacking any self-deposited calcareous incrustation (subgenus Lithophaga ) or shell smooth and (partly) covered with own incrustations, particularly on the posterior half (subgenus Leiosolenus Carpenter, 1857 ). Umbones subterminal, ligament deep-set, along a toothless hinge. Remarks. Anal and branchial siphons fused as in Adula , but the branchial part lacks papillae on its edge in Lithophaga . In L. lithophaga , there is a tonguelike structure, the valvular membrane, with minute papillae at the base of the branchial sipho ( List 1902: pl. 7, fig. 6 ). Some examples of valvular siphonal membranes with central lappet and lateral digits in three L. ( Leiosolenus ) species are figured in Wilson (1985 : figs. 5 and 7a, c), those of B. fusca by Wilson & Tait (1984: figs. 4, 5A, B) . All seem to be quite variable and, therefore, of no help for species determination.