150 Wortman — Studies of Eocene Mammalia in the 



vore ; but a careful examination clearly reveals their carnivo- 

 rous character. As is usual among the Carnassidents, the iirst 

 molar is the largest of the series, which decreases in size pos- 

 teriorly. Where the full number is present, it is a very 

 general rule that the first greatly exceeds the second in size ; 

 but in the present case the decrease is much more gradual. 

 The crowns have the anterior part much elevated and divided 



into the three usual cusps. In- 

 stead, however, of the external 

 one being much larger and 

 higher than the other two, they 

 are more nearly equal (figure 23). 

 They are placed at the points of 

 a triangle whose sides are sub- 

 Figure 23.— Lower molars of equal, the shortest side, or base, 



Oodertes herpes toides Wortman ; in- i • _ j- ±. j • i j v, 



side view; three times natural size. \ Gm ^ directed in wards and a lit- 



(Cotype.) tie forwards. Between the outer 



and anterior cusps a short more 

 or less imperfect shear is developed, and a posterior shear is 

 also present between the outer and inner cusps. The heel is 

 composed of a central fore and aft secant ridge, on the inner 

 side of which the border is slightly raised, thus giving the first 

 step in the formation of the basin-shaped talon. The succeed- 

 ing teeth are alike in structure, with the exception that the 

 principal shear is proportionately less developed on account of 

 the reduction in size of the anterior cusp of the trigon. 



Of the superior dentition, figure 24, the single incisor, if it 

 is correctly referred to this category, has a rather narrow, 

 pointed crown, somewhat flattened upon its posterior surface, 

 and corresponds most nearly with the second. The canine 

 resembles that of the lower jaw, showing about an equal 

 degree of stoutness and curvature. The first premolar is not 

 preserved in any of the specimens. The second has an 

 obtusely-pointed crown, with a small posterior basal cusp and 

 an indistinct cingulum upon the inner margin of its base. 

 The third is thicker, somewhat triangular in cross-section, 

 with a more pronounced posterior basal cusp and a stronger 

 internal cingulum. In many of the viverrines, more particu- 

 larly the Herpestine and Paradoxurine sections, the third pre- 

 molar has a tendency to develop an internal cusp, and the 

 formation of the internal cingulum may be regarded as the 

 initial stage in this process. 



At first sight it would appear that the fourth superior pre- 

 molar is of a too highly developed sectorial character to corre- 

 spond with that of the lower jaw ; but, curious as this may 

 seem, there can be no possible doubt of the association. This 

 tooth, however, betrays its primitive character in the large size 



