Posidoniella variabilis

Hind, W. (1896-1905). A monograph of the British Carboniferous Lamellibranchiata. <em>Monograph of the Palaeontographical Society.</em> 50 (237): Vol. 1, Part I: 1–80, pls 1–2 (1896); 51 (240): Part II: 81–208, pls 3–15 (1897); 52 (244): Part III: 209–276, pls 16–25 (1898); 53 (250): Part IV: 277–360, pls 26–39 (1899); 54 (253): Part V: 361–476, pls 40–54 (1900); 55 (258): Vol. 1 [Title p. & Index, Errata], 477–487 (December 1901); 55 (258): Vol. 2, Part I. 1–34, pls 1–6 (1901); 57 (269): Part II. 35–124, pls 7–21 (1903); 58 (274): Part III: 125–216, pls 22–25 (1904); 59 (280): Vol. II: [Title p. and Index]: 217–222 (1905).