Beede.] Carboniferous Invertebrates. 173 



forward curve, so as to form a broad, rounded, very shallow 

 sinus. Length, 2.85 inches ; height, from the ventral margin 

 to the middle of the dorsal side, 1.36 inches; length, from the 

 base to the line drawn from the beaks across to the most ele- 

 vated part of the posterior extremity, 1.50 inches; greatest 

 convexity, near the middle, 1.11 inches ; breadth of the posterior 

 hiatus, 1.07 inches ; height of the posterior hiatus, 1.44 inches." 

 Range and distribution : Upper Coal Measures ; Kansas City, 

 Lawrence. 



