Cycl. 



172 



H.I7.5./7 



Cyclonema bilix. {Pleurotomaria lilix.) Rogers, page 

 lift .A ^^^' fig. "620. Loraine formation. (Conrad, 

 ^ ^^ Jour. Acad. N. Sci. Phila. Vol. 8, 1842. Tren- 

 ton and Hudson river formations ) II c^ Illh^ — 

 The genus Cyclonema (thread-wound) was es- 

 tablished by Hall in Pal. N. Y., Vol. 2, 1852, 

 R. SZO page 89; Ulix being its type species. 



Cyclonema cancellatum. {littorina cancellata.) Hall, 



GeoL, 1843, page 72, figs. 17, 5, a young 

 individual finely and beautifully can- 

 cellated over its whole surface. This 

 marking became obliterated as the 

 animal grew old, see figs. 6, front and back views. Abundant 

 in the Sodus and Rochester green ( Clinton) shale ; also in the 

 Rochester and Medina Pentamerris strata. — Va. 

 Cyclonema concinnum ( Concinna), See Appendix. 

 Cyclonema hamiltoniae. See Appendix. 

 Cyclonema leavenworthana. {Pleurotomaria leaven- 

 yj ^' worthana^ Hall, Trans. Alb. Ins. Vol. 



^ •"" "^^ 4, 1856.— Whitfield, Bull. 3, Am. Mus. 



N. H. 1882, plate 8. ) Collett's Indiana 

 Rt. 1882, page 363, plate 31, figs. 29, 

 magniiied twice ; fig. 30, natural size ; 

 In^. /DsT. P/.3/T'^^^ fig. 31, magniiied twice and showing 

 opening to chamber. — Suhcarh. limestone at Alton, 111., and 

 Spergen Hill, Lanesville and Bloomsburg, Ind. This shell 

 varies its form greatly with age, the young being rounder, the 

 old with longer spires. It is not a Pleurotom,aria, nor a Murcli- 

 isonia, because it has no special spiral band. It is near Pleti- 

 rotomaria trilineata. ^I 



Cyclonema percarinatum. {Pleurotomaria percarinata. 

 Hall, Pal. N. Y. Vol. 1, 1847, Trenton and 

 Hudson river groups.) Emmons, Amer. Geol. 

 I, ii, page 223, plate 5, fig. 7 ; like other gas- 

 teropods (snails) of the Trenton limestone at 

 Middleville, N. Y., rarely smooth and perfect; 

 therefore hard to identify ; associated with 

 Atrypa hemiplicata., Cyrtolites compressus^ 

 'and Cyrtolites trentoneiisis. — Trenton, lie. 



. -C 



Em.A.G.is 



