94 CARBONIFEROUS LAMELLIBRANCHIATA. 



Productus semireticulatus. 

 Chonetes Laguessiana. 

 Spirifer glaber. 



— bisulcatus. 

 Orthis resupinata. 

 Athyris planosulcata. 

 Discina nitida. 

 Lingula mytiloides. 



Modiola peralata. 



— transversa. 

 Myalina lamellosa. 

 Nucula gibbosa. 

 — pequalis. 

 Posidoniella semisulcata. 

 Sanguinolites sulcata ? 

 Aviculopecten fibrillosus. 

 And the Crustacean Dithyroearis 



Streptorhynchus crenistria. testudineus. 



The genera Inoceramus and Myalina are stated in the " Appendix on the 

 Fossils " of the memoir mentioned above to occur in this quarry. It is possible 

 that the shells now described as Posidoniella were at that time indicated by the 

 name Inoceramus, to which genus the sulcations on the anterior part of the shell 

 give it a marked resemblance. 



Posidoniella l^vis, Brown, sp., 1841. Plate VI, figs. 12 — 14, 24. 



Catilltjs L-Evis, Brown, 1841. Trans. Manchester Geo]. Soc , vol. i, p. 226, 



pi. vii, fig. 66. 



— Kellti, Brown, 1841. Ibid., p. 226, pi. vii, fig. 67. 



— mitojtus, Brown, 1841. Ibid., p. 226, pi. vii, figs. 71, 72. 



— l.evis, Brown, 1849. Illustr. Foss. Conch., p. 167, pi. lxvii, fig. 22. 



— Kellti, Brown, 1849. Ibid., p. 167, pi. Ixviii, fig. 17. 



— hinutus, Brown, 1849. Ibid., p. 167, pi. Ixviii, figs. 18, 19. 

 Posidotua mtnuta, Brown, 1849. Ibid., p. 168, pi. lxi**, fig. 32. 



— ? Gibsoki, Salter, 1862. Mem. Geol. Surv. Gt. Britain : Geol. Country 



round Wigan, 2nd edit., p. 35, fig. 1 a. 



— Wild, 1892. Trans. Manch. Geol. Soc, vol. xxi, p. 400, 



pi. ii, fig. 8. 



Specific Characters. — Shell convex, somewhat smooth, obliquely ovate. The 

 anterior border, truncate and straight, descends almost vertically downwards, 

 passing with gradually rounded curve into the inferior border, which is extensive 

 and almost semicircular. The posterior border is obliquely truncate, straight 

 above, convex below. The hinge-line is short and straight, making a very obtuse 

 angle behind with the posterior border. The umbones are small, convex, twisted 

 forwards to become terminal, not elevated above the hinge-line. Proceeding from 

 the umbo obliquely backwards and downwards, the valves are convexly swollen, 

 the anterior slope being more rapid, and the line of greatest convexity being 

 anterior. Above and behind, the valve, compressed and expanded, is subalate. 



Interior at present unknown. 



