Pentremites Burlingtonensis, Meek fy Worthen. 



Fage 

 Fig. 16. The distal end of a radial sinus as seen after removal of the lancet-plate and side 

 plates, so as to expose the under lancet-plate which completely conceals the 

 hydrospires. Subcarboniferous, Iowa. Coll. Wachsmuth. x 3 4 



Pentremites Godoni, Defrance, sp., p. 157. 

 Fig. 17. Section of the calyx from above, showing the water-vascular ring and its extensions 

 into the lancet-canals. The spiracular canals leading to the hydrospires are 

 also shown. Subcarbonifcrous, Alabama. X 6 101 



