292 CARBONIFEROUS LAMtiLLIBRANCHIATA. 



Edmondia XJNiONiFOEMis, Morris, 1854. Cat. Brit. Foss., 2nd edit., p. 202. 



— 31' Coy, 1855. Brit. Pal. Foss., p. 503. 



— — Eichwald, 1860. Lethsea Rossica, vol. i, p. 1034. 



Non — Salter, 1861. Mem. Geol. Surv. Gt. Brit., Iron Ores 



Gt. Brit., pt. 3, pp. 221,222, pi. i, 

 fig. 29. 



— — Meek and Worthen, 1866. Geol. Surv. Illinois, vol. ii, 



Pal., p. 346, pi. xxvii, figs. 6 a, b. 



— — Young and Armstrong, 1871. Trans. Geol. Soc. Glasg., 



vol. iii, Suppl., p. 51. 



— — — 1876. Carb. Foss. West of 



Scotland, p. 54. 



— — B. Etheridge, jun., 1876. Ann. Mag. Nat. Hist., ser. 



4, vol. xviii, p. 99, pi. iv, fig. 3. 

 Miller, 1877. Amer. Pal. Foss., p. 191. 



— — Bigsby, 1878. Thesaurus Devonico - Carboniferus, 



pp. 306, 307. 

 Non — — de Koninck, 1885. Ann. Mus. Roy. d'Hist. Nat., 



torn, xi, p. 29, pi. xi, figs. 32 — 

 36 ; pi. xiii, figs. 42, 43. 



— pr^lata, de Koninck, 1885. Ibid., p. 36, pi. xiii, fig. 26. 



— — Etheridge, 1888. Brit. Foss., pt, 1, Palaeozoic, p. 284. 

 Cotnp. — ? decoeata, de Koninck, 1885. Ibid., p. 48, pi. x, figs. 15 — 20. 



— ? PB2ECOX, de Koninck, 1885. Ibid., p. 48, pi. x, figs. 31, 32. 



— tenuilineata, de Koninck, 1885. Ibid., p. 44, pi. x, figs. 23, 24. 



— ? pulchella, de Koninck, 1885. Ibid., p. 52, pi. x, figs. 21, 22. 



— ? anodonta, de Koninck, 1885. Ibid., p. 49, pi. iv, figs. 7, 14. 



Specific Characters. — Shell transversely broadly ovate, gibbose. The anterior 

 end is small, convexly curved, but comparatively deep in a dorso-ventral direction. 

 The anterior border is semicircularly rounded, passiug without a break into the 

 inferior border, which is much less convex and extended. The posterior border is 

 obtusely rounded without any approach to angulation at its junction with the 

 superior and inferior borders. The hinge-line is nearly as long as the shell, and 

 slightly arched. The umbones are obtuse, twisted forwards and incurved, some- 

 what raised, close, and situated in the anterior quarter of the hinge-line. There 

 is no lunule and no escutcheon. The posterior end is somewhat narrowed in its 

 dorso-ventral diameter by the approach of its upper and lower borders. The 

 valves are regularly and convexly swollen, there being no oblique line, but the 

 dorsal slope is somewhat flattened. The cardinal margin is simple and sharp, 

 coming immediately into contact with its fellow. External ligament-groove short 

 and narrow. 



Interior. — The anterior adductor muscle-scar is shallow, and situated just 

 within the antero-superior angle; the posterior is situated within the dorsal 



