V. S. GEOLOGICAL SURVEY 



MONOGRAPH 55 PLATE XXV 



SUPERIOR DECIDUOUS AND PERMANENT GRINDING TEETH OF MENODUS GIGANTEUS 



Ai, Am. Mus. 497, deciduous premolars and firA permanent molars of left side, crown view^; A2, the same, showing permanent teeth 

 embedded in the alveolar region. Both t^vo'thirds natural si^e 



