List of Lower Silurian Fossils, Cincinnati Group. 67 



Nautilid^. Ammonitid^. 



Shell straight in . . Orthoceras . . Baculites. 



bent on itself in . Asoceras . . Pt^^choceras. 



curved . . . Cyrtoceras . . Toxoceras. 



spiral . . . Trochoceras . . Turrilites. 



discoidal . . Gyroceras . . Crioceras. 



discoidal and produced in Lituites . . Ancyloceras. 



involute in . . Nautilus . , Ammonites. 



Famil}' Orthocerafidoi. Gr. orthos, straight; keras, a horn. 

 Geuus Orthoceras, Breynius. Gr. orthos, keras. 



114 Orthoceras amplicameratum, Hall. L. amjplus, large; camera, 



an arch. 



115 Carleyi, Hall and Whitfield. 



116 Duseri, Hall and Whitfield. 



117 juuceum, Hall. Jj. junceus, ViY\\%\\. 



118 Ortoni, Meek. 



119 turbidum, Hall and Whitfield. L. turbidus, disturbed. 



120 Byrnesi, S. A. Miller. 



121 Duryi, S. A. Miller. 



122 Fosteri, S. A. Miller. 



123 Halli, S. A. Miller. 



124 Harperi, S. A. Miller. 



125 Mohri, S. A. Miller. 



126 transversum, S. A. Miller. L. trans, across; verto, I turn. 



127 Cincinnatiensis, S. A. Miller. 



Genus Ormoceras, Stokes. Gr. ormos, a chain or necklace; keras, a 



horn. 



128 Ormoceras tenuifilum, Hall. L. tenuis, fine; filmn, a thread. 



Genus Endoceras, Hall. Gr. endon, within; keras. 



129 Endoceras annulatum, Hall. L. annulatus, ringed. 



130 approximatum, Hall. L. ad, proximo, I come near. 



131 proteiforme, Hall. Gr. proteuo (protos), to be first; /orma. 



132 subcentrale, Hall. L. sub, centrum, centre. 



133 magniventrum, Hall. L. magniis, great; venter, belly. 



Family Gomphoceratidoe. Gr. gomjthos, a club; keras. 



Genus Gomphoceras, Sowerby. Gr. gomphos; keras. 



134 Gomphoceras eos, Hall and Whitfield. Gr. eos, dawn. 

 Family Phragmoceratidce. Gr. phragmos, a partition; keras. 



