(5) Cetomorpha, or whales and dugongs; (6) Ungulata; (7) Primates. Of these groups, the first and second, third and fourth, fifth and sixth, can perhaps, to judge from palæontological evidence, be combined into three greater groups, as indicated by the fossil Esthonychida, Ictopsida, and Condylarthra, in addition to the ancestral Primates, or Lemuravida, as the fourth large branch of the ancestral-tree where this has reached the placental level. Among none of the first three branches can we look for the ancestors of the Primates. The Lemuravida, therefore, represent a branch equivalent to the three other branches.
21. Stage of Lemures, or Prosimiæ, comprising the older members of the Primates, consequently approaching most nearly to the Lemuravida. The limbs are modified into pentadactyle hands and feet of the arboreal type, and are protected by nails. The dentition is of the frugivorous or omnivorous type, with an originally complete series of teeth,
