408 CALIFORNIA ACADEMY OF SICENCES. [Proc. 3D Ser. 



Horizon and locality. Upper Trias, Noric stage (above 

 the limestone with Trofites subbttllatiis) , Genesee Valley, 

 Plumas County, California, Brock Mountain, on divide 

 between Squaw Creek and Pitt River, Shasta County, Cali- 

 fornia; and in Muttleberry Canyon, nine miles southeast of 

 Lovelock, Humboldt County, Nevada, in a branch of the 

 West Humboldt Range. 



The figured specimens came from Genesee Valley, from 

 the so-called Swearinger slates of Diller, near Robinson's 

 Ranch, Plumas County, California. 



