503 



Orbio. 



Orbiculas and Lingulas, of several different species, living 



\ 



Ow. Lin. 



together, are shown in Owen's medal-ruled fig. of a slab from 

 the Falls of St. Croix, Iowa. St Croix sandstone (not the 

 Potsdam of N. Y.) supposed at one time to be quite barren of 

 fossils; now a treasury of species differing from those of the 

 Potsdam. II a. \ — 



Orbicula ? Mentioned by H. D. Rogers in Geol. 



Penn. 185S, as found in Utica and Hudson river formations^ 

 Illa^b, 



Orbicula ? In C. E. Hall's collections at Bell's 



Mills, Blair Co., Pa., 1875, Proc. Am. Phil. Soc. Jan. 5, 1876. 

 Clinton formation^ V a. 



Orictoblattina occidna. Scudder. An insect found in 

 Mazon cr. nodule, 111. Proc. A. N. S. Phila. 1885, p. 37. In the 

 Lacoe collection. Coal Measures. XI I L 

 5 



