88 ORIGIN AND CLASSIFICATION 
Carnivora. As no other order can claim the family Galeopithecide, 
it is placed here, but rather for convenience than for any other 
consideration, since it has but little if any relationship with any of 
the other members. Its isolated position is indicated by assigning 
it a distinct subordinal rank. 
The Chiroptera have always been placed near the Insectivora ; 
but they are really a highly specialised group, as much isolated 
from all other mammals by the modification of their anterior limbs 
in adaptation to aerial locomotion, as the Cetacea and the Sirenia, 
by the absence of hind limbs, are specially adapted for an aquatic 
life. 
Lastly, the Primates, which in any natural system must be 
placed at the head of the series, are divisible into two very distinct 
groups—one containing the various forms of Lemurs (Lemuroidea), 
and the other the Monkeys and Man (Anthropoidea). Whether 
the Lemuroidea should form part of the Primates (according to the 
traditional view), or a distinct order altogether removed from it, 
is as yet an undetermined question, for both sides of which there 
is much to be said. There can, however, be no doubt that the 
Anthropoidea form a perfectly natural group, presenting a series 
of tolerably regular gradations from the Marmosets (Hapale) to 
Man. Certain breaks in the series, however, enable us to divide 
it into five distinct families:—Hapalide or Marmosets ; Cebide or 
American Monkeys, with three premolar teeth on each side of each 
jaw; Cercopithecide, containing the majority of Old-world Monkeys ; 
Simiide, consisting of the genera Hylobates, Simia, Gorilla, and 
Anthropopithecus, the true Man-like Apes; and, lastly, Hominude, 
containing the genus Homo alone. 
Subclass I. PRoTOTHERIA. 
Order i. MonoTREMATA—Monotremes. 
Fam. 1. Ornithorhynchide—Duck-bill. 
2, Echidnide—Spiny Anteater. 
Group. MULTITUBERCULATA.! 
Fam. 1. Plagiaulacide—Plagiaulax. 
2. Polymastodontidee—Polymastodon. 
3. Tritylodontide—tTritylodon. 
Subclass IT. METATHERIA. 
Order ii. Marsuprati14—Marsupials. 
Suborder 1. Potyproropont1a—Polyprotodonts. 
1 The names of the groups containing only extinct forms are printed in heavier 
type than those which contain species still existing. 
