BIVALVE SHELLS. 217 



Genus 3. LAJONKAIRIA, Desk. 



Animal ovato-oblongum, compressiusculum ; pallium integrum 

 antice apei'tum, iuferne posticeque clausum ; tracheis binis co- 

 aihmatis lateialiter compressiusculis, subicqualibus, trachea bran- 

 cliiali majore, ad aperturam ciliata. Pes minimus, corapressus, 

 linguiformis ; labiarum appendices elongatie, angustsK, acuta;, 

 triangulares. Branchia; carnosfe breves, subsquales, quadran- 

 gulares, postice latiores, truncatae. 



Testa ovato-oblonga vel subquadrangularis, decussata, tenuis ; 

 cardine angusto, in valva dextra bidentato, in sinistra tridentato, 

 dentibus minimis, divarieatis ; nymphis brcvibus; ligamentum 

 externum angustum, breve; cicatriculaj musculorum minim£e 

 subrotundataj ; impressio pallii brevis, sinu postico latissimo, 

 profundissimo, triangulari terminata. 



Tellina (sp.), Schrot. (1/86) EM. iii. 18. no. 11. 



G}«e/. (1788) p. 32.31. no. 11. 

 Venus, Mont. (1808) Test. Brit. Suppl. p. 48. 

 Venerupis, Payraud. (1826) Cat. Moll, de Corse, p. 36. 



Desk. (1836) Lamk. ed. 2. vi. 164. 

 Rupellaria, Petit (1851), Jonrn. de Conch, p. 289. 

 Tapes (sp.), Sow.jun. (1852) Thes. Conch, p. 695. 



1. Lajonkairia decussata, Desh. 



L. testa rotundato-quadrangula, antice brevissima, striis longi 

 tudinalibus creberrimis sub lente granulosis exarata ; striisqu 

 incrementi irregularibus decussata. 



Encycl. Meth. pi. 272. f. 2. a, b. 



Venus Candida, Scacchi (non Gmel.), Cat. Conch. Neap. p. 7. 



Venerupis decussata, Phil. Moll. Sicil. p. 20. pi. 3. f. 5 ; ii. 20. 



no. 2. 

 Venerupis Lajonkairii, Payr. Cat. Moll, de Corse, p. 36. pi. 1. 



f. 12, 13. 



Desh. Lamk. An. s. Vert. ed. 2. vi. 164. 

 Rupellaria Lajonkairii, Petit, Journ. de Conch. 1851, p. 289. 

 Tapes Lajonkairii, Sow. jun. Thes. Conch, p. 695. pi. 150. f. 120. 

 Junior. Tapes subquadrata, Sow. jun. loc. cit. p. 695. pi. 150. 



f. 119. 



Hah. Mare Mediterraneum. 



2. Lajonkairia substriata. 



L. testa subquadrata, parva, sinuata, alba, striis tenuissimis con- 

 centricis et costellis minutis aqualibus decussata ; latere antico 

 brevissirao, umbonibus subterminalibus ; margine dorsali recto, 

 ascendente ; latere postico ti-uncato. 



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