563 



Orthoc. 



Orthocerata, mostly undescribed species of western Kinder- 

 hook limestone aspect, (I. 0. White, Q4, 83) abound in the 

 Meadville upper limestone^ Crawford Co. — X. 



Orthoceras ? in loose piece of brown sandstone, 



Spec. 2797, Ennis hill, Pleasantville, Venango Co. — X. 



Orthoceras ? Stevenson's K3, 311, in Fayette and 



Westmoreland Cos. Lower Carhoniferous. XIII? 



Orthoceras ? small species, plentiful in Black Foss. 



limestone (Barren Measures) Stevenson, Trans. A. P. S. XV, 

 p. 26; L, p. 21. Also in Indiana Co. H3, p. 230.— X/K 



Orthoceras ? several ill-defined casts and impres- 

 sions, found by Heilprin among the Mill Creek Limestone 

 fossil collection of Wyoming Hist. Soc. Wilkes-Barre, Pa. 

 Geol. Sur. An Rt. 1885, p. 457, 1000' above Pottsville Con- 

 glomerate. XIV. 



Orthoceratites. See Orthoceras. 



Orthodesma contractum, Hall. {Orthonata contracta 

 4. ^^p^|» ^ 3. Hall.) Pal. N. Y., 



-->w«ii^sife. ..^^^^^^1^' Vol. 1, 1847.— Pal. 



Ohio, Vol. 2, 1875, 

 page 96, plate 2, fig. 

 4, left side of typical 

 specimen, showing folds of hinge slope ; 5, another specimen, 

 diff*erent, from near Waynesville, O. — Cincinnati group^ III 



Orthodesma curvatum, H. & W. Pal. Ohio, Vol. 2, 1875, 



, page 95^ 



PaLO. 



;^^^0. plate 2, fig. 



6, left side, 



' \ ; showing 



general 



features of 



a specimen 

 from near 



Waynesville, O. Shape characteristic. Front muscular scar 

 strong, medium size, very near front end ; hind scar not ob- 

 servable. Surface marked by many concentric wrinkles, and 

 by finer irregular growth-lines. At first suppsed to be Modio- 

 lopsis nasuta. Hall, of III h in N. Y.; but hind end three times 

 as long in proportion, etc. — /// b. 



