PLATE X. 



PAGE. 



DELTODUS POWBLLII, St. J. and W 154 



Fig. la. Mandibular posterior tooth, left ramus, view from above; 1 b, do., trans- 

 verse profile, outline from inner margin; 1 c, do., from outer margin, 

 outline; 1 d, do., outline from antero-lateral border; 1 e, do., from pos- 

 tero-lateral border; 1 f, showing character of punctation of coronal 

 surface, enlarged. Carboniferous limestone; Utah. National Museum. 

 Fig. 2 a, b. c, d. Deltodus Mercuni, Newb. Lower Carb.; Santa Fe, New Mexico, 

 0. St. John. 



DELTODUS PBOPINQUUS, St. J. and W 156 



Fig. 3 a. Mandibular posterior tooth, right ramus, view from above; 3 b, do., trans- 

 verse profile from inner margin; 3 c, do., from outer margin; 3d, do., 

 longitudinal profile from antero-lateral border; 3 e, do., postero-lateral 

 border. Coal No. 5, Carlinville, 111. 



Fig. 4 a, b, c, d, e. Similar views of a maxillary posterior tooth, right ramus. Coal 

 No. 5, Carlinville, 111., Mr. Alex. Butters. 



