84 CARBONIFEROUS LAMELLIBRANCHIATA. 



thoroughly, but whether or no the species is identical with those from Lancashire 

 and Yorkshire I am unable to say. The shape of Posidonomya fracta, Meek, 

 reminds one of Posidoniella Isevis, but in the figure the shell has more marked 

 undulations and intermediate stria?; in this character it agrees more with 

 P. vetusta. 



Posidoniella vetusta, Sowerby, sp., 1829. Plate V, figs. 9, 10, 10a, 11, lib; 



Plate VII, figs. 2, 2 a. 



Inocekamus vetustus, J. and J. de C. Soioerby, 1829. Min. Conch., vol. vi, p. 162, 



pi. dlxxxiv, fig. 2. 



— — 8. Woodivard, 1830. Synop. Table Brit. Organ. Eemains, 



p. 17. 



— —J. Phillips, 1836. Illustr. Geo!. Yorkshire, vol. ii, p. 211, 



pi. vi, figs. 3, 4. 



— — A. Goldfuss, 1836. Petref. Germ., vol. ii, p. 107, pi. cviii, 



fig. 5 a. 

 Posidonomta tetusta, de Koninck, 1843. Anim.Foss. Carbonif. Belgique, p. 141, 



pi. vi, figs. 1 a, 1 b. 



— — Morris, 1843. Catalogue British Fossils, p. 118. 

 Inocebamus vetustus, M'Goy, 1844. Synops. Carbonif. Fossils Ireland, p. 77. 

 Posidonomta tetusta, Bronn, 1848. Nomenclat. Palseont., p. 1034. 

 Posidonia tetusta, Broion, 1849. Illustr. Fossil Conch. Gt. Britain and Ireland, 



p. 168, pi. lxvii, fig. 15. 

 Posidonomta tetusta, d'Orbigny, 1850. Prodr. Paleont. Stratigr., p. 138. 



— Morris, 1854. Catal. Brit. Foss., edit. 2, p. 181. 

 Ambontchia tetusta, 8. P. Woodward, 1854. Manual of the Mollusca, p. 261. 



— — M'Coy, 1855. Syst. Descript. Brit. Palasoz. Fossils, p. 482. 

 Posidonomta tetusta, Eichwald, 1860. Lethsea Rossica, vol. i, p. 943. 

 Inocebamus vetustus, Griffith, 1862. Journ. Geol. Soc. Dublin, vol. ix, p. 93. 

 Ambontchia tetusta, Young and Armstrong, 1871. Trans. Geol. Soc. Glasgow, 



vol. iii, Supplement, p. 45. 

 Posidonomta tetusta, Armstrong , Young, and Robertson, 1876. Catal. Western- 

 Scottish Fossils, p. 52. 



— — Bigsby, 1878. Thesaurus Devonico-Carboniferus, p. 293. 



— — Etheridge, 1885. British Foss., vol. i, Palseoz., p. 276. 

 Posidoniella tetusta, de Koninck, 1885. Faune du Calcaire Carbonifere, pt. 5 ; 



Ann. Musee d'Hist. Nat. Belgique, 

 vol. xi, p. 184, pi. xxxi, figs. 1, 2, 

 8—11, 17, 18, 23—26. 



Specific Description. — Shell for the most part regularly gibbose, quadrately 

 ovate, produced downwards somewhat obliquely, alate, and compressed posteriorly 



