416 Proceedings of the Ohio State Academy of Science. 



ORTHOCERAS OKAWENSE ?— Worthen. 



1883. Orthoceras Okawensis. Worthen, Geol. Surv. Ill, Vol. VII, 

 p. 324. 

 Chester limestone : Okaw Bluffs near Red Bud, Randolph County, 

 Illinois. 

 1890. Orthoceras okawense. Worthen, Geol. Surv. III., Vol. VIII, p. 149, 

 pi. 26, fig. 3. 

 Chester limestone : Near Red Bud, Randolph County, Illinois. 



Description. ■ — • "Shell elongate, slender, very gradually tap- 

 ering to the apex ; septa concave, about four of them in the 

 space of one diameter. Siphuncle sub-central ; surface markings 

 unknown. 



''This ffhell has a general resemblance to O. rushense, Mc- 



FiG. 36. — Orthoceras okawense"^ A view of a fragment of a shell re- 

 ferred to this species. 



Chesney of the upper Coal Measures, but differs from it in the 

 position of the siphuncle which in our species is decidedly sub- 

 central [Worthen, 1890]." 



Horizon and locality. — Maxville limestone. 

 Shale-nodular zone : Krof t Bridge, White Cottage. 



