Obthoc. 



542 



Orthoceras annulatum. ( Orthoceras laphami^ and Orth- 



oceras nodo- 

 cos tatum^ of 

 McChesney, 

 1860, New Pal. 

 Fossils, pp. 90, 

 94 ; also , 

 Trans. Chi- 

 cago Ac. S. 

 Vol. 1, p. 53, 

 pi. 9, H^ 5.) 

 Collett's Indi- 

 ^' ana Eeport of 

 <t 1881, p. 358, 

 pi. 38, fig. 1 (cut off' to get into this page), natural size^ show- 

 ing surface markings a little too strongly. — Hall, Geol. N. Y. p. 

 110, fig. 40, 1. (Sowerby, Min. Conch., Vol. 2, p. 133, pi. ix, 

 f. 5, 1818.) Clinton and Niagara formations^ V a^h, — See, 

 also. Pal. Ohio, Vol. 2, 1875, p. 147, pi. 9, fig. 1,— Vh 



Orthoceras arcuoliratum. (Hall, Pal. N. Y. 1847, Black 

 •jj.-^ ■ ^ River and Trenton). Em- 



mons, Am. Geol. I, ii, 1855, 

 149, plate 12, fig. 4; spiral, 

 e:m. A.&.155.5 Pi'-z slightly elevated waving 



ridges, separated by spaces equal to their breadth, and finely 

 striated lengthwise. — Trenton. II c. 



