Orthis. 



516 



Orthis eminens, Hall, Pal. JSf. Y. Vol. 3, 1859, pi. XI, figs. 



NY. V^^c, 





7, 8, 9, 12, 12. Lower Helderlerg. — In Pennsylvania collections 

 (00, p. 234) specimens 604-7 (three) in F. & G.'s coll. at Man- 

 sing's quarry, near Hazardville. Carbon Co., Pa., from Low» 

 Helderberg, F/.— Also (000, p. 166), spec. 187-4 (three) from 

 Perry Co., three miles east of Ikesburg ; and spec. 216-3 (five) 

 from other outcrops of the Lower Helderherg chert heds^ VI. 

 Orthis flssicosta, Hall. Pal. N. Y. Vol. 1, 1847. Em- 



mons, Amer. Geol. Vol. 1, part 2, p. 195, pi. 9, figs. 7 <^, 5/ 

 valves unequally convex ; about 20 ribs angular and divided 

 twice or thrice near the middle. — Same as Orthis dichotoma 

 (S. A, Miller). Pal. Ohio, Vol. 1, p. 106, pi. 8, fig. 6 a, S, c, 

 ventral, dorsal, cardinal views ; 6 6?, magni-fied surface striae 

 crossed by minute lines of growth; 6 ^, profile of 6 <^/ 6 /, 

 inside of a smaller dorsal valve, without visible muscular 

 scars ; 6 ^, inside of ventral valve, hinge margin broken, show- 

 ing obscure muscular cavity; 6/^,, inside ventral, small hinge 

 teeth, no cavity. — Hudson river formation.^ Lllh, 



Orthis flabellulum, [O. callactis?) Hall, p. 105, fig. 36,5. 

 Niagara formation. ( 0, ilaheUum^ name pre- 

 occupied by Sowerby, 1839.) Found in speci- 

 men 506-8, of C. E. Hall's collections, 1875, 

 at Bell's Mills, Blair Co., Pa., from Clinton 

 lime shale., V a. 



h.sS^S* 



