Memoirs Carnegie Museum, Vol. v. 



Plate XXXIII. 



1. Bivibnuichia protntctila Eigenmann. (Type.) llo mm. Xo. 1873. 2a-2c. (lills of left side, begin- 

 ning with the first at 2a. 3. Roof of mouth anil oill-chamhers, showing valves. 4. Floor of mouth and 

 gill-chamber. 5. Sagittal section, showing valves of the roof of the mouth. 



