LYO. MAC.] 



LAMELLIBRNACHIATA. 



487 



Fro. 842. Lunulicar- 

 dium marcellense. 



fragile, Hall, 1843, (Avicula fragilis,) 

 Geo. Rep. 4th Dist. N. Y., p. 222, and 

 Pal. N. Y., vol. 5, pi. 71, figs. 1-14, Gen- 

 esee Shale. 



fragosum, Meek, 1877, (Posidonomya fra- 

 gosa,) U. S. Geo. Expl. 40th Parallel, 

 vol. 4, p. 92, Carboniferous. 



marcellense, Van- 

 uxem, 1842, (Cy- 

 pricardites mar- 

 cellensis,) Geo. 

 Rep. 3d Dist. 

 N. Y.,p. 146, and 

 Pal. N. Y., vol. 5, 

 pi. 71, figs. 15-16. 

 Marcellus Shale, 

 orbiculare, Hall, 

 1885, Pal. N. Y., 

 vol. 5, p. 436, Marcellus Shale, 

 ornatuin, Hall, 1843, (Pinnopsis ornata,) 

 Geo. Rep. 4th Dist. N. Y., p. 244, and 

 Pal. N. Y., vol. 5, p. 437, Portage Gr. 

 rude, Hall, 1884, Pal. N. Y., vol. 5, pi. 71, 



fig. 17, Marcellus Shale, 

 transversum, Hall, 1885, Pal. N. Y., vol. 5, 



p. 439, Chemung Gr. 



Lyansia, Turton, 1822. Not found in Paleo- 

 zoic rocks. 



concava, see Sedgwickia concava. 

 LYRIOPECTEN, Hall, 1884, Pal. N. Y., vol. 5, 

 p. 3. (Plates and Explanations.) [Ety. 

 tyrion, a lyre ; Pecten, a genus.] Dis- 

 tinguished from Aviculopecten by the 

 shorter hinge-line and very small an- 

 terior wing; surface with strong rays. 

 Type L. magnificus. 



alternatus, Simpson, 1889, Diet. Foss. Pa., 

 p. 366, and Trans. Am. Phil. Soc., p. 

 446, Chemung Gr. 

 anomiiformis, Hall, 1884, Pal. N. Y., vol. 



5, pt. 1, p. 53, Up. Held. Gr. 

 cymbalon, Hall, 1884, Pal. N. Y., vol. 5, 



pt. 1, p. 47, Ham. Gr. 

 dardanus, Hall, 1884, Pal. N. Y., vol. 5, 



pt. 1, p. 41, Up. Held. Gr. 

 fasciatus, Hall, 1884, (Pernopecten fascic- 

 ulatus,) Pal. N. Y., vol. 5, pt. 1, p. 55, 

 Chemung Gr. 



interradiatus, Hall, 1884, Pal. N. Y., vol. 

 5, pt. 1, p. 44, Ham. Gr. 



FIG. 843. Lyriopecten orbiculatus. 

 macrodontus, Hall, 1884, Pal. N. Y., vol. 



5, pt. 1, p. 46, Up. Held. Gr. 

 magnificus, Hall, 1884, Pal. N. Y., vol. 5, 



pt. 1, p. 51, Up. Chemung Gr. 



orbiculatus, Hall, 1843, (Avicula orbicu- 

 lata,) Geo. Rep. 4th Dist., N. Y., p. 202, 

 and Pai. N. Y., vol. 5, pt. 1, p. 42, 

 Ham. Gr. 



parallelodontus, Hall, 1884, Pal. N. Y., 

 vol. 5, pt. 1, p. 40, Up. Held. Gr. 



polydorus, Hall, 1884, Pal. N. Y., vol. 5, 

 pt. 1, p. 50, Chemung Gr. 



priamus, Hall, 1884, Pal. N. Y., vol. 5, pt. 

 1, p. 54, Chemung Gr. 



solox, Hall, 1884, Pal. N. Y., vol. 5, pt. 1, 

 p. 56, Up. Chemung Gr. 



tricostatus, Vanuxem, 1842, (Avicula 

 tricostata,) Geo. Sur. 3d Dist. N. Y., p. 

 179, and Pal. N. Y., vol. 5, pt. 1, p. 48, 

 Chemung Gr. 



LYRODESMA, Conrad, 1841, Ann. Geo. Rep. 

 N. Y., p. 51. ' [Ety. lyra, a harp; desma, 

 a ligament.] Equivalve, inequilateral, 

 semicircular; hinge plate with 6 to 8 

 angular, crenulated teeth radiating 

 from beneath the beak upon a more 

 or less rounded platform. Type L. 

 planutn. 



cincinnatiense, Hall, 1871, 24th Rep. 

 N. Y. St. Mus. Nat. Hist., p. 227, Hud. 

 Riv. Gr. 



planum, Conrad, 1841, Ann. Geo. Rep. 

 p. 51, Hud. Riv. Gr. 



poststr i a t u m , 

 E m m o n s , 

 1842, (Nucu- 

 lana poststri- 

 ata,)Geo.Rep. 

 N. Y., p. 399, 

 and Pal. N.Y., 

 vol. 1, p. 151, Black Riv. Gr. 



pulchellum, Hall, 1847, Pal. N. Y., vol. 



1, p. 302, Hud. Riv. Gr. 

 MACRODON, Lycett, 1845, Murch. Geo. Chelt. 

 [Ety. macros, long; odoiis, a tooth.] 

 Shell oblong, very inequilateral, mod- 

 erately tumid, a byssal sinus in the 

 anterior third of the ventral margin 

 anterior edges of the adductor impres- 

 sions prominent; hinge teeth at the an- 

 terior end 

 few,slightly 

 oblique or 

 nearly at 

 right angles 

 to the hinge- 

 line be- 



beak 1 * be* FlQ ' 815 - Macrodon obsoletus. 

 coming more oblique toward the an- 

 terior end ; posterior part of the hinge- 

 line, from beak to anal angle, occupied 

 by one to three long lateral teeth. 



carbonarius, Cox, 1857. (Area carbona- 

 rius,) Geo. Sur. Ky., vol.3, p. 567, Coal 

 Meas. 



chemungensis, Hall, 1870, Prelim. No- 

 tice Lam. Shells, p. 14, and Pal. N. Y., 

 vol. 5, pi. 51, figs. 11-16, Chemung Gr. 



cochlearis, Winchell, 1863, Proc. Acad. 

 Nat. Sci., p. 16, Marshall Gr. Prof. 

 Hall suggests that it is a syn. for M. 

 parvus. 



Fio. 844. Lyrodesma post- 

 striatum. 



