HAPALIDA7—CEBID. 787 
PLATYRRHINA. CATARRHINA, 
No sigmoid flexure in the colon A sigmoid flexure. 
descendens. 
Never more than a_ slight The cecum is conical; with a 
narrowing at the end of the vermiform appendix in Apes. 
cecum, which is usually bent 
like a hook. 
No hints of a ‘secondary dis- A “‘ secondary discoidal placenta” 
coidal placenta.” (only hinted at in Anthropoid 
Apes). 
Family 1. Hapatip# (= Arctopithecini). Marmosets 
The marmosets are the smallest monkeys, not much 
larger than squirrels. They live in companies in the 
Neotropical forests, especially in Brazil, and feed on insects 
and fruit. 
In addition to the general Platyrrhine characters, the 
following are noteworthy. 
Their dentition, 2737, is distinctive, for other Anthropoidea 
2132 
have 4 molars. The molars have three main tubercles 
instead of the usual four. The pinna of the ear is very 
hairy. The tail is long, bushy, and non-prehensile. The 
pollex is long, but not opposable; all the digits have a 
pointed claw except the short opposable hallux. The 
cerebral hemispheres have few convolutions. The marmo- 
sets often bear three young ones at a birth, whereas the 
other monkeys usually bear but one. There are two 
genera, Hapale and Midas. 
Family 2. Cesip#. American Monkeys 
The American monkeys occur throughout tropical 
America, but are most at home in Brazil. In addition to 
the general Platyrrhine characters, the following are note- 
worthy. The tail is long except in Brachyurus, and is 
often prehensile. The digits have nails, not claws; the 
thumb if present is opposable. The pinne are more or 
less naked. The dentition is characteristic, for there are 
six back teeth ; the formula being 2133. All are uniparous. 
