The platyrrhine and catarrhine monkeys have their primitive ancestor among extinct forms of the Lemuridae.

We may thus ascend to the Lemuridae; and the interval is not very wide from these to the Simiadae.

LEMURIDAE.- Agroupof four-handed animals, distinct from the monkeys and approaching the insectivorous quadrupeds in some of their characters and habits.

The blood of the Lemuridae (Nuttall) gives no reaction or an extremely weak one, that of the other mammals none whatever.