1897.] On the Affinities of Tarsius : 689 
decidedly mixed type, and probably not far from the common 
stem form, which gave origin to both suborders of the Pri- 
mates. 
In regard to Tarsius, it is evidently a type nearly between 
the Lemurs and Apes, but with many essential characters be- 
longing to the former group. Some of its Anthropoid charac- 
ters are nascent, so to speak; they are just developing, and, as 
in the case of the orbit of Tarsius, it is not yet fully differen- 
tiated into the higher type of the true Anthropoids. It appears 
most likely that the group of fossil Lemurs with reduced 
canines and enlarged incisors, Mixodectes, Microcherus, were 
not in the line leading to the Lemurs proper, but may have 
been related to Cheiromys. These genera in.their turn arose 
` out of a generalized insectiverous-like type with a normal den- 
tition, which was also the ancestral form of the true Lemurs. 
The Anthropoids diverged from a lemurine stock probably not 
earlier than the Upper Eocene. This deduction is supported 
by the fact that the first Lemurs to appear are insectivorous in 
their affinities ; later, in the Upper Eocene, Lemurs are found 
with quite Ape-like skulls and dentition, and, moreover, not 
until the Miocene do true Anthropoids appear. 
I shall conclude this paper with a quotation from a Memoir 
of Sir Wm. Turner’s, whose extensive investigations on the 
placentation of Mammals are well known to all morphologists : 
“ In the case of the Lemurs it will, I think, be considered by 
most zoologists that the characters of the teeth, the general 
configuration of the skeleton, the unguiculate digits, the hand- 
like form of the distal part of the extremities, the presence of a 
calcarine fissure in the cerebrum and the pectoral position of 
at least two of the mamma, are characters which indicate that 
the Lemurs have much closer affinity with those mammalian 
orders with which.it has been customary to associate them, 
than with the Perissodactyla, Suina and Cetacea. Collectively, 
these characters ought, I think, to be regarded as more valu- 
able indications of structural affinity than should the presence 
in the Lemurs of a non-deciduate diffused placenta with a large 
allantois be regarded as indications of structural dissimilarity 
from the Apes and Insectivora, though the placenta in the 
latter is deciduate and discoid and the allantois aborted.” 
