Ortiijs. 



512 



Orthis clytie, Hall, 14th Annual Keport, 1861, p. 90; 15th 

 III L 4 5 Annual Keport, 1862, 



"^ pi. 2, tig. 4, dorsal view; 



5, interior of ventral 

 valve. Also, Pal. Ohio, 

 Vol. 2, 1875, p. 75, pi. 

 1, figs. 18, 19, from the 

 Hall'ISik fiiij.j?^ J^2.,^^^-^^^-^^/,7^ .original specimen's on 

 which the species was founded ; 18, interior of ventral valve; 



19, dorsal exterior. — 

 Cincinnati group. — 



Orthis costalis. (Hall, Pal. N. Y. Vol. 1, 1847, Chazy 



limestone.) Emmons, Amer. Geol. Vol. 1, 

 part 2, 1855, p. 235, pi. 3, fig. 21 S, c, 26 a, 

 2f^ b ; about 32 strong folds on the two valves, 

 one of which is flatter than the other. In 

 the thin Chazy limestone beds, especially 

 near Chazy village, Clinton Co., N. Y. 

 Emmons, //5.— ''O. costatus^"^ specimen 

 204-7 (GO, p. 232) in Fellows' coll. mill- 

 dam, Eeedsville, Mifiiin Co. Trenton^ lie. — C. E. Hall reports 

 it from Kishicoquillis Valley, Proc. A. P. S. Jan. 5, 1876, in 

 Chazy., II h. 



Orthis erispata. Emmons, p. 404, fig. 113, 5. Loraine 

 (Hudson river) formation. Illh. 



Orthis davidsoni, De Verneuil. Bull. Geol. Soc. France, 



VA^.^5?,^^,,.^ a fr ^^^* ^' 1840, Tipper Silurian. Geology of 



Canada, 1863, p. 312, fig. 318 a., dorsal; J, 



side views. In Logan's chapter on the 



Medina and Clinton formations of Canada 



_ ™,^ ;.^i8iw West. Vaf 



