No. 2.] THE HARD PARTS Of WHE MAMMALIA. - 145 
to Condylarthra with tritubercular teeth, of which many are 
known from the Puerco beds, or vice versa; and the quadri- 
tubercular forms from corresponding quadritubercular Condy- 
larthra, of which many are known, or vice versa. 
Szxth. The anthropoid line may be traced directly through 
the lemurs to the Condylarthra. The changes which have 
taken place in the skeleton are slight, and consist among other 
points in a rotation of the first row of carpal bones outwards 
on the second row, in the anthropoid apes and man, similar to 
that which has occurred among the Ungulata, but it has not 
become so pronounced. 
As a result we get the general phylogenetic scheme as shown 
on the following page. 
In this diagram, divisions of greater and lesser rank are 
mixed, so as to display better some of the relationships. Thus 
all the divisions whose names stand on the right side of the 
middle vertical line are unguiculates ; and those on the left side 
of the line, excepting Sirenia and Cetacea, are ungulates. The 
three names in the middle vertical line are those of the sub- 
orders of the Taxeopoda. 
In the table! (p. 147), the history of some of the diagnostic 
characters of the Mammalia is shown, in connection with the 
passage of geologic time. With further knowledge it will be 
possible to construct similar tables explanatory of the history of 
the evolution of all characters of animals, so that the one now 
given is only preliminary. 
1 From the Proceedings of the American Association for the Advancement of Sct- 
ence, for 1883. 
