Orthoc. 



554 



taoe marking. Sixteen rings to an inch in a specimen less 

 than a half inch thick ; 10 in two other cases ; 13 in a speci- 

 men i inch thick at small end; rings slightly oblique; in one 

 case oblique by the width of a chamber ; twice as numerous 

 and sharper than in 0. crotalum. Closely near 0, ihex^ Sow- 

 erby, and 0. articulatum. Hamilton soft shales^ Seneca lake 

 and coarse shales^ Cayuga lake. VIII c. — In Pennsylvania, 

 found as specimen 805-25, of C. E. Hall's Bell's Mills, Blair 

 Co., collections from Hamilton^ VIII c. Also Claypole's 

 Spec. 5-126 (000, 11749) from Barnett's Mill, Perry Co., Pa.; 

 99-4 (12383) from Drumgold's tannery ; 233-7 (12837) Rose- 

 burg; all three found in Hamilton upper shales. VIII c, 



Orthoeeras ohioense (instead of 0, pelops, var. ohio- 

 ense,) Hall, 111. Dev. Foss. 1876, Up. Held. (I give one of 

 Hall's figures of 0. pelops.wndier that name, below.J — Found 

 in Pennsylvania, 00, p. 235, at Marshall's Falls, Monroe Co. 

 Spec. 801-28, in Hamilton strata^ VIII <?. 



Orthoeeras olorus. {Orthoeeras vertehrale.) Rogers, page 



1r#^^ R Rn5l ^^^' ^S- ^'08. Trenton for- 

 .If^pi iC.'^-oi^^ mtiiJio^. (Hall, Pal. N. Y. 



Vol. 1,1847. "Vertebrale" 

 had been occupied by Schlot- 

 \ \ heim in 1820, and by Eich- 

 waldinl840.) He. 



Orthoeeras Ontario. Clarke, Bull. 16, U. S. G. S. 1885, p^ 



VlWe. 



51, pi. 3, fig. 1, natural size (1^ inches of the pointed end cut 

 ofl";) narrow, low, acute angled, rather distant rings, say 30 in 

 all in 5| inches, sloping abruptly to surface of shell, leaving 

 flat spaces between. Naples (Upper Genesee) Hack shales. 

 Ontario Co., N. Y.— VI lie'. 



