PEC. PER.] 



LAMELLIBRANCHIA TA. 



501 



Hist., p. 189, and Pal. N. Y., vol. 5, pi. 

 72, figs. 31-33, Up. Held. Gr. 



Fio. 885. Paracyclas elliptica var. occidentalis. 



erecta, Hall, 1885, Pal. N. Y., vol. 5, p. 



445, Chemung Gr. 

 fissa, Hall, 1883, Pal. N. Y., vol. 5, pi. 72, 



tigs. 35, 36, Schoharie grit. 

 hamiltonensis, Winchell, 1866, (Lucina 

 hamiltonensis,) Rep. Low. Pen. Mich., 

 p. 95, Ham. Gr. 

 ignota, Hall, 1883, Pal. N. Y., vol. 5, pi. 



72, fig. 34, Chemung Gr. 

 lirata, Conrad, 1838, (Posidonia lirata,) 

 Ann. Rep. N. Y., p. 116, and Pal. N. Y., 

 vol. 5, pi. 72, figs. 1-19, Corniferous Gr. 

 ohioensis, Meek, 1871, 

 Proc. Acad. Nat. Sci. 

 PhiJ., p. 62, and 

 Ohio Pal., vol. 1, p. 

 248, Cornif. Gr. 

 peroccidens, Hall & 

 Whitfield, 1877, 

 U. S. Geo. Expl. 40th ^Parallel, vol. 4, 

 p. 248, Devonian. 



retusa, Hall, 1843, (Lucina ? retusa,) Geo. 

 Rep. 4th. Dist. N. Y., p. 246, Por- 

 tage Gr. 

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



p. 444, Chemung Gr. 

 sabini, White, 1876, Proc. Acad. Nat. Sci., 



p. 31, Chemung Gr. 

 tenuis, Hall, 1883, Pal. N. Y., vol. 5, pi. 



72, figs. 20-22, Ham. Gr. 

 varysburgensis, Williams, 1887, (Lucina 

 varysburgia,) Bull. 41, U. S. Geo. 

 Sur., Portage Gr. 



Fio. 886. -Paracyclas 

 ohioensis. 



FIG. 887. Pernopecten aviculatns. 



wyomingensis, Williams, 1887, Bull. 41, 



U. S. Geo. Sur., Portage Gr. 

 Pecten, Mueller, 1776. This genus is un- 

 known in the Palaeozoic rocks. 

 acutialatus, see Aviculopecten acutialatus. 

 armigerus, see A. armigerus. 



aviculatus, see Pernopecten aviculatus. 



broadheadi, syn. for Aviculopecten car- 

 bon i ferns. 



cancellatus, see Aviculopecten cancellatus. 



carboniferus, see A. carboniferus. 



clevelandicus. see A. clevelandicus. 



coloradoensis, see A. coloradoensis. 



convexus, see A. convexus. 



crenulatus, see Crenipecten crenulatus. 



dolabriformis, see Aviculopecten dolabri- 

 formis. 



duplicatus, see A', duplicatus. 



hallianus, D'Orbigny, 1847, syn. for Avi- 

 culopecteu cancellatus. 



halli, see A. halli. 



hawni, Geinitz, 1866, Carb. und Dyas, p. 

 36, syn. for A. carboniferus. 



missouriensis, see A. mi*souriensis. 



neglectus, see Euchondria neglecta. 



occidentals, see A. occidentalis. 



providencensis, see A. providencensis. 



radiali*, see Pseudomonotis radialis. 



ringens, see Aviculopecten ringens. 



striatus, see A. striatus. 



tenuilineatus, see Streblopteria tenuilineata. 



utahensis, see Aviculopecten utahensis. 

 Pernachactas, Castelnau, 1843, Syst. Sil., p. 

 44. Not recognized. 



FIG. 889. Perno- 

 pecten limifor- 



FIG. 888. Pernopecten limiformis. Hinge-line. 



PERNOPECTEN, Winchell, 1865, Proc. Acad. 



Nat. Sci. Phil., p. 125. [Ety. from the 

 shells Pema and Pea- 

 ten.} Shell like Pecten 

 hinge with a central 

 cartilage pit and a 

 crenulated hinge plate 

 on each side below the 

 hinge margin. Type 

 P. limiformis. 

 aviculatus, Swallow 

 1858, (Pecten avicu- 

 lus,) Trans. St. Louis 



Acad. Sci., p. 213, and 



Geo. Sur. 111., vol. 5, p. 588, Coal Meag 

 cooperensis, Shu- 



mard, 1885, (Ayic- 



ula cooperensis,) 



Geo. Rep. Mo., p. 



206, Waverly or 



Choteau Gr. 

 fasciculatus, see Ly- f; v ; 



rippecten fasciatus. 

 limiformis, White & 



Whitfield, 1862, 



(Aviculopecten li- 



maformis,) Proc. 



Bost. Soc. Nat. 



Hist., vol. 8, p. 295, Marshall Gr. 

 limatus, Winchell, 1865, Proc. Acad. Nat. 



Sci., p. 126, Marshall Gr. 



33 



