Eastman. — Mylostomid deutition. 



EXPLANATION OF PLATE. 



Upper pavement dentition of Mylostoma variabile Newberry, from the Cleveland 

 shale of Sheffield, Ohio. X j- a.p.p., anterior pair of palatopterygoid plates : 

 right (Amer. Mus. Nat. Hist., Cat. 43 G), left {idem, 42 G). p.p.p., posterior 

 palatopterygoid plates : right (Amer. Mus. Nat. Hist. Cat. 3591), left (Mus. 

 Comp. Zool. Cat. 1437). Specimens belonging to different individuals, rear- 

 ranged in their inferred natural position. 



