Lajonkairia is a genus of marine bivalve molluscs in the subfamily Petricolinae of the family Veneridae, commonly known as carpet shells.MolluscaBase eds. (2021). MolluscaBase. Lajonkairia Deshayes, 1855. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=138330 on 2022-02-05
Characteristics (Original description in Latin) The animal is ovate-oblong in shape and somewhat compressed. Its mantle is entire, being open at the anterior end but closed at both the inferior and posterior sections. It possesses two joined siphons that are laterally compressed and nearly equal in size, though the branchial siphon is larger and fringed with cilia at its opening. The foot is very small, compressed, and tongue-shaped, while the appendages of the lips are elongated, narrow, sharp, and triangular. The gills are fleshy and short, nearly equal in size, and quadrangular in form; they broaden toward the posterior end, where they are abruptly truncated.
The shell itself is ovate-oblong or somewhat quadrangular, thin in structure, and decorated with a decussated pattern. The hinge is narrow; the right valve features two teeth, while the left valve has three. These teeth are very small and arranged in a divaricate fashion. The nymphs are short, and the external ligament is narrow and brief. The muscle scars are very small and nearly round. Finally, the mantle impression is short and terminates in a posterior sinus that is remarkably wide, very deep, and triangular in shape. Deshayes, G. P. (1853-1855). Catalogue of the Conchifera or bivalve shells in the collection of the British Museum. British Museum, London, Part I. Cyprinidae, Veneridae and Glauconomidae, pp. ii + 216 pp
Species Lajonkairia cancellata (Gmelin, 1791) Lajonkairia digitalis (E. A. Smith, 1916) Lajonkairia divaricata (Lischke, 1872) Lajonkairia elegans (H. Adams, 1870) Lajonkairia lajonkairii (Payraudeau, 1826) † Lajonkairia rupestris (Brocchi, 1814) Lajonkairia substriata (Montagu, 1808)
Synonyms Lajonkairia digitale [sic]: synonym of Lajonkairia digitalis (E. A. Smith, 1916) (incorrect gender ending)
References
External links Jukes-Browne A.J. 1910. On Petricola, Lucinopsis, and the family Petricolidae. Proceedings of the Malacological Society of London, 9: 214-224. Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca. in: Costello, M.J. et al. (eds), European Register of Marine Species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Patrimoines Naturels. 50: 180-213 Fischer, P. (1880-1887). Manuel de conchyliologie et de paléontologie conchyliologique, ou histoire naturelle des mollusques vivants et fossiles suivi d'un Appendice sur les Brachiopodes par D. P. Oehlert. Avec 23 planches contenant 600 figures dessinées par S. P. Woodward.. Paris: F. Savy. Published in 11 parts (fascicules), xxiv + 1369 pp., 23 pls