534 CHARACTERS OF PRIMATES CHAP. 
group to which so many others appear to converge. It is dis- 
puted, for example, whether the Chriacidae among extinct Lemurs 
are rightly placed, or whether they should be referred to the 
Creodonta. The number of primitive characters seen among the 
Primates, even in Man himself, is remarkable. Of these the more 
important are the five digits of both limbs and the plantigrade 
walk, the presence of clavicles and of a centrale, and the absence 
of a third trochanter. All these features distinguish the early 
Kutheria. 
SuB-ORDER 1. LEMUROIDEA.! 
The animals known as Lemurs, from their nocturnal and ghostly 
habits, are on a lower level of organisation than the other division 
of the Primates. Even the external form enables the members 
of the present sub-order to be readily distinguished from the 
higher Anthropoidea. The head is more like that of a Fox, with 
a sharp muzzle; it lacks the human expression of the face of even 
the lower among the Apes. The long tail is never prehensile, and 
there is never any trace of cheek pouches or of integumental 
‘allosities, which are frequently so characteristic of the Apes. 
The Lemurs agree with the remainder of the Primates in haying 
pectoral mammae (sometimes abdominal ones are present im 
addition, and in Hapalemur—in the male at least—there is a 
mamma upon each shoulder), in having opposable thumbs and 
toes, and in the flattened digits. The tail varies from complete 
absence (in the Zoris) to a great length and bushiness in 
the Aye-aye. The pectoral limbs are always shorter than 
the hind-limbs; the reverse is occasionally the case in the 
Anthropoidea. A curious contrast between the two divisions 
of the Primates concerns the digits of the hands and feet. In 
the Anthropoidea it is the hallux or pollex which is subject to 
great variation. In the Lemurs, on the contrary, the thumb 
and great toe are always well developed, but the second or 
the third digit constantly shows some abnormality; thus the 
singular elongation of the third digit of the hand in Chiromys 
and the absence of the index in the Potto.2 In all Lemurs the 
' See Dr. Mivart’s papers in Proc. Zool. Soc. 1864, -65, -66, -67, and -73 for 
osteology and teeth. 
* Murie and Mivart, Trans. Zool. Soc. vii. 1869, p. 1. 
