Orthoc. 



558 



port of 1881, page 322, plate 28, figs. 11, 12, and plate ^3, figP. 

 1, 2. Specimens frequently flattened and shell destroj-ed; 

 septa usually obliterated. Niagara formation, F J. 



Orthoceras sordidum, Billings. Geology of Canada, 1863, 

 ^^ ^- — 59 page 121, fig. 39. Calciferous sand- 



stone {Lower Silurian) formation. 

 II a. 



Vm e. 



Geo/. Ca'Vtf^^^*^ /5?^3. 



Orthoceras stebos. Clarke, Bull. 16, U. S. G. S. 1885, 



page 29, plate 2, fig, 15, magniHed 12 

 times^ a unique specimen, from the Gen- 

 essee shale of Ontario Co., N. Y. — 

 VIII e, 

 CIK. B.ie. ^^"^^ 2. 



Orthoceras strix, H. & W. Pal. Ohio, Vol. 2, 1875, p. 



149, plate 9, fig. 3, internal cast of type specimen (the figure 

 in Pal. Ohio, being 8 inches long, has been cut and only the 

 two ends used) ; transverse section broadly oval, or subcircular 

 (partially compressed, as. shown by cylindrical small end); 

 flutings striated (?) lengthwise, but no trace of cross-striation 

 noticeable. Much like 0. columnare^ Hall, but with much 

 larger flutes, and tapers faster. Differs still more from 0, 

 cadmus.) Billings, Sil. Foss. Anticosti. Niagara limestone at 

 Yellow Springs, 0. — Vb, 



