102 
cusp 5, is difficult to say for certain, the former alternative may 
be the most probable. We meet thus with an example of the 
vanishing of the "reptilian cone”. — In Hyænodon the construction 
is almost the same, except that 6 has almost disappeared, 1 is 
very small and 4 and 5 have united into one sharp narrow cusp. 
The chåracteristic of the carnassial of Carnivora primitiva is the 
equivalence of 4 and 5, the small size of 1 and the length of 3. 
In Carnivora vera we must look at the milk-carnassial (dp”) 
and the permanent carnassial (p) separately. The most obvious 
difference between them is that cusp 6 with its root is placed 
nearly in the middle of the inner side of dp?, whereas it is placed 
on or near the anterior end of p:; this fact is due to an important 
difference in the construction of the teeth. If we examine dp? of 
a primitive carnivore, e. g. Viverra civetta 
(fig. 3, diagr. 6), we find at the anterior 
end a rather large cusp (1) separated by 
a long shallow notch from the high me- 
dian cusp (5); inside the notch a small 
rounded cusp is placed, connected with 
Fig.3. Viverra civetta,dp2. the anterior border of the heel (6), the 
(Viewed from above, ”/1, and — posterior border is joining the main me- 
Fromm 10 ly het Side, 14); dian cusp. The hindmost cusp (3) is 
long and rather low. Cusp 2 is evidently wanting, and the small 
cusp inside the notch between 1 and 5 must be 4. This cusp 4 
is very varying in size in Felis spp. and Hyæna spp., but 
rarely longer than 1 and always placed somewhat inside this 
cusp, sometimes just in front of the anterior sharp edge of 5, thus 
s 
frudte. ke É 
rr HLIYU FN 
i j i 
Fig. 4. 1 Felis pardus, 2 F. onga, dp? (from above and 
m the outer side). Y; 
