120 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [VolY. 



General Section of Jura-Trias in Southeastern Idaho and Western Wyoming. 



The thicknesses in this section are estimated, and when the region is 

 more thoroughly studied may have to be somewhat modified. 



The fossils described in Dr. White's paper came from ISTo. 2, which I 

 have called the "Meekoceras Beds," from the new genus named by Pro- 

 fessor Hyatt. They are the following : 



Meelioceras aplanatum White. 



Meelxoceras muslibaclianus White. 



Meelioceras gracilitatis White. 

 Besides these, the following were obtained : 



Arcestes ? cirratus White. 



Arcestes f sp. % 



Arcestes f sp. "? 



Terebratula semisimplex White. 



Terebratula augusta Hall and Whitfield % 



Eumicrotis curfa M. & H. 



Aviculopecten idahoensis Meek. 



Aviculopecten alius White. 



Aviculopecten pealei White. 



GervilUa sp. ? 

 2^0. 3 yielded no fossils. 

 ^o. i yielded the following : 



Fentacrinus asteriscus. 



Gamptonectes hellistriatus. 



Trigonia sp. ? 



Myacites sp. ? 



