PEC. — PER.] 



LAMELLIBRANCHIA TA. 



501 



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

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



Fig. 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. 

 Phil., p. 62, and 

 Ohio Pal., vol. 1, p. 

 248, Cornif. Gr. 

 Fig. 886. -Paracyclas peroccidens, Hall & 

 ohioensis. 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, 18S7, (Lucina 

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

 Sur., Portage Gr. 



Fig. 887.— Pernopecten aviculatus. 



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- 

 boniferus. 



cancellatus, see Aviculopecten cancellatus. 



carboniferus, see A. carboniferus. 



clevelandicus. see A. clevelandicus. 



coloradoensis, see A. coloradoensis. 



convexus, see A. convexns. 



crenulalus, see Creni pecten crenulatus. 



dolabriiormis, see Aviculopecten dolabri- 

 formis. 



duplicatus, see A. duplicatus. 



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

 culopecten 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. 



occidentalis, see A. occidentalis. 



provide ncensis, see A. providencensis. 



radvtli*, 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- 

 mis. 



Fig. 888. --Pernopecten limiformis. Hinge-line. 



Pernopecten, Winchell, 1865, Proc. Acad. 



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

 shells Perva and Pec- 

 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 Meas 

 cooperensis, Shu- 



mard, 1885, (Avic- 



ula cooperensis,) 



Geo. Rep. Mo., p. 



206, Waverly or ,jjP 



Choteau Gr. 

 fasciculatus, see Ly- f, 



riopecten fasciatus. %f. 

 limiformis, White & 



Whitfield, 1862, 



(Aviculopecten li- „ 



rnafnrmi^ Prop FlG - 890.— Pernopecten 



maiormis,; rroc. shumardanus. 



Bost. Soc. Nat. 



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

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



Sci., p. 126, Marshall Gr. 



33 



