VERTEBRATA AT VERO. 
65 
MEASUREMENTS OF LOWER JAW AND TEETH IN MILLIMETERS. 
Length from rear of mi to front of symphysis. 
Height of jaw at front of pm 4 - 
Height of jaw at rear of mi- 
Thickness of jaw at front of pm 4 -- 
Thickness of jaw at rear of mi- 
Length of symphysis in front_ 
Length of tooth row pm 3 —nil- 
Length of pm 3 - 
Thickness of pm 3 - 
Length of pm 4 - 
Thickness of pm 4 _:_ 
Length of m 4 - 
Thickness of m 4 - 
Fore-and-aft diameter of canine at base_ 
Side-to-side diameter of canine at base- 
Fossil Jaw 
6739 
173028 
— 45-5 
47.0 
14.0 
16.0 
17.0 
17.0 
7-5 
7-5 
' 7 o 
8.0 
23-5 
22.5 
29.0 
30.0 
__ 8.0 
7.6 
4-5 
4.2 
10.1 
10.8 
- 5-0 
5 -i 
12.0 
12.2 
- 5 -i 
5-3 
7-5 
8.0 
7.0 
6.0 
On comparing the jaw with a series of skulls from Florida it is 
found that the fossil shows apparently no essential specific differ¬ 
ences. The carnassial of No. 6739 has the notch deeper than any 
of the existing specimens, but a few approach it closely. 
A right tibia seems not to differ essentially from that of the 
living form. When compared with No. 173028, United States 
National Museum, from Florida, differences appear; but these are 
probably only of individual importance. 
From Port Kennedy cave Cope (Jour. Acad. Nat. Sci. Phila., 
Vol. II., 1899, p. 250) described Lynx calcaratns, which was so 
closely related to L. ruffus that originally he referred it to this 
species. 
III. GENERAL CONCLUSIONS. 
Of the 43 species which have been enumerated in this paper it 
will be seen that 17 are regarded as being extinct. This amounts 
to 40 per cent. If the fishes, amphibians, and reptiles are consid¬ 
ered apart from the others, they present only 26 per cent, of extinct 
species. These low forms are more likely to persist than are the 
more highly organized mammals. Nevertheless, a large propor¬ 
tion of the cold-blooded animals are represented in the collection by 
very meagre remains; and it is possible that with more abundant 
materials species distinct from those now living might be recog- 
