gg PROCEEDINGS OF THE NATIONAL MUSEUM vol.68 



and its enormous sharp-edged median cusp, the base of which lies 

 toward the inner side of the bar. The denticles on the tv/o ends 

 of the bar are set farther forward toward the outside of the bar. 

 All of these are, as usual in the genus, sharp edged and in part 

 confluent with five rather short broad-based denticles on the shorter 

 end and five similar but larger and longer denticles occupying the 

 outer two-thirds of the longer ends of the bar. Finally, four or five 

 minute denticles are between the latter and the base of the main 

 cusp. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



H olotype.— C^t. No. 11019, U.S.N.M. 



BRYANTODUS NELSONI. new species 



Plate 10, lig. 9 



Bar rather thick, slightly curved, the anterior half curved down- 

 ward and inward with numerous laterally confluent denticles (9-12). 

 Main cusp large, thick, very prominent bent somewhat backward. 

 ■Posterior end of bar with large, less curved although otherwise 

 similar denticles as on anterior end. 



This species, as well as Bryantodus insolens, belongs to a peculiar 

 group of the genus suggesting in the form of the part in front of 

 the main cusp the corresponding part of Hindeodella. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Holotype.—C2ii. No. 11020, U.S.N.M. 



BRYANTODUS SUBBREVIS, new spscics 

 Plato 10, fis. 15, in 



Our figures represent opposite teeth of this new species showing 

 the short form slight curvature of base, semiovate outline and de- 

 cidedly recurved denticles which distinguish it from B. radiatus 

 and its allies. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant. 

 Tenn. 



C oty pes.— C2it. No. 11027, U.S.N.M. 



BRYANTODUS CURVATULUS. new species 



Plate 9, fig. 13 



Tooth curved tapering rapidly backward, the anterior end un- 

 known, broken. The posterior denticles about 10 compactly ar- 

 ranged, inclining forward, subequal in size, the main cusp not greatly 

 longer but considerably wider than the others. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Holotype.—Q,2X. No. 11032, U.S.N.M. 



