138 ANNALS NEW YORK ACADEMY OF SCIENCES 



Powell, p. 110. U. S. Geological and Geographical Survey of the Terri- 

 tories, 1876. 



Unio nucaJis Meek and Ha.yden, Phila. Acad. Nat. Sci., Proc. 1858, 

 •p. 52. 



U7iio ivillistoni Logan, The Stratigraphy and Invertebrate Faunas of 

 the Jurassic Formation in the Freezeout Hills of Wyoming. Kans. 

 Univ. Quart., vol. ix, p. 133, pi. 31, fig. 10, 1900. 



Fig. 92. — The same slide and field as fig. 91, with crossed nicols. 



This shows the banded feldspars and the granular quartz which has replaced the volcanic 



ash. 



Unio Imighfi Logan, Tlie Stratigraphy and Invertebrate Faunas of the 

 Jurassic Formation in the Freezeout Hills of Wyoming. Kans. Univ. 

 Quart.y vol. ix, p. 134, pi. 31, figs. 7, 9, 1900. 



Unio haileyi Logan, The Stratigraphy and Invertebrate Faunas of the 

 Jurassic Formation in the Freezeout Hills of Wyoming. Kans. Univ. 

 Quart., vol. ix, p. 134, pi. 31, figs. 4, 6, 8, 11, 1900. 



