No. 1.] TRITUBERCULAR MOLAR. 9 
It may be readily seen, in consideration of these facts, that 
the appearance of tritubercular superior molars in the genus 
Homo constitutes a reversion to the lemurs, and not to the 
anthropoid apes or to the monkeys proper. And among lemurs 
the reversion is most probably to that type which presents the 
closest resemblance to Homo in other parts of the dentition. 
The genus which answers most nearly to this requirement 
among those at present known, is Anaptomorphus. 
Figure 1.—Two species of Anaptomorphus. Fig. a, A. evulus, lower jaw from 
above X2. Figs. 4, c, d, A. homunculus; 6, c, natural size; d, 3 natural size. Both 
Po 
4 
from Eocenes of the Rocky Mountains. 
In studying the dentition of man, I have examined the crania 
contained in the following six collections: those of the Academy 
of Natural Sciences of Philadelphia; of the Army Medical Mu- 
seum of Washington; of the College of Physicians of Philadel- 
phia; of the University of Pennsylvania; of the Boston Society 
of Natural History; and of my own museum. The first of these 
is especially valuable on account of the negro, Egyptian, and 
Hindu crania it contains. My acknowledgments are due to the 
Board of Curators, of which Professor Leidy is chairman, for the 
opportunity of studying it. I am also indebted to the Boston 
Society of Natural History, and its learned curator, Professor 
