LEIOPTERIA LUNULATA. 11 



Letopteria lfnulata, Phillips, sp., 1880. Plate II, fig's. 7—11 ; Plate III, figs. 2, 



3 ; Plate IV, figs. 4, 5, 8. 



Gervillia LUNULATA, Phillips, 1836. Geol. Yorks., pt. ii, p. 211, pi. vi, fig. 12. 

 AvicuLA LUNULATA, de Koninclc, 1843. Descr. Auim. Foss. Belgique, p. 129, pi. iii, 



figs. 21 a, h. 



— — Morris, 1843. Cat. Brit. Foss., 1st edit., p. 106. 



— — M'Coy, 1844. Synops. Carb. Foss. Ireland, p. 84. 



— La;viGATA, M'Coy, 1844. Ibid., p. 84, pi. xiii, fig. 23. 



— iNFORMis, M'Coy, 1844. Ibid., p. 83, pi. xiii, fig. 21. 



— RECTA. M'Coy, 1844. Ibid., p. 84, pi. xiii, fig. 24. 



— ANGUSTA, M'Coy, 1844. Ibid., p. 83, pi. xiii, fig. 20. 



— LUNULATA, Broivn, 1849. Illust. Foss. Concb., p. 163, pi. Ixvii, fig. 17. 



— — d'Orbicjny, 1850. Prodrome Palcout., vol. i, p. 137. 



— — Morris, 1854. Cat. Brit. Foss., 2ud edit., p. 162. 



— RECTA, Morris, 1854. Ibid., p. 162. 



Pterinea LUNULATA, M'Coy, 1855, Brit. Pal. Foss., p. 480. 



— L«viGATA, M'Coy, 1855. Ibid., p. 479. 



AvicuLA LUNULATA, Eicliwuld, 1860. Lethaea Rossica, vol. i, p. 956, pi. xxxvii, fig. 16. 



— — Bigsby, 1878. Thesaurus Devonico-Carboniferus, p. 287. 

 Leiopteria LUNULATA, de Koninch, 1885. Ann. Mus. Roy. d'Hist. Nat. Belg., 



torn, xi, p. 188, pi. XXX, fig. 4. 

 AvicuLA LUNULATA, Etheridge, 1888. Brit. Fo.>«s., pt. i, Palaeozoic, p. 270. 



— INFORMIS, Etheridge, 1888. Ibid., p. 270. 



— L^viGATA, Etheridge, 1888. Ibid., p. 270. 



— RECTA, Etheridge, 1888. Ibid., p. 271. 



— ANGUSTA, Etheridge, 1888. Ibid., p. 270. 



Specific Character^;. — Shell inequilateral, obli(|uely limulate, compressed. 

 Anterior wing short, narrow, compressed, almost pointed. The anterior border is 

 oblique, somewhat sinuous, and descends downwards and backwards. The lower 

 border is broader and convex, passing up behind to meet the posterior margin, 

 which is falciform and concave. The hinge-line is long and straight, produced 

 backwards in a short, narrow process, which does not extend as far posteriorly as 

 the posterior inferior angle. The umbones are small, raised slightly above the 

 hinge-line, very little swollen, and placed far forAvards, but not terminal. 



The body of the shell is obliquely and somewhat lunulately swollen, flattened 

 and expanded doAvnwards near the posterior inferior angle. This convexity is 

 gradual in front, Intt posteriorly it is marked off from the depressed and flattened 

 posterior wing by a well-marked lunate convex ruga, which passes from the umbo 

 to the postero-inferior angle. 



Interior. — A large muscle-scar, subcentral. Hinge with small, oblique anterior 

 teeth and elongated posterior lateral teeth. Pallial line entire. 



