The callitrix is a species of ape described in some medieval bestiaries. It is said to always give birth to twins. It is said that it hates one but loves the other, just as the cericopithicus

Cericopithicus

Cericopithicus is a species of ape described in some medieval bestiaries. It is said to always give birth to twins, of which it will always hate one and love the other. The callitrix, cynocephalus and satyrus apes of medieval bestiaries are described as doing this. The cericopithicus apes are said...

, cynocephalus, satyrus

Satyrus (ape)

Satyrus is a species of ape described in some medieval bestiaries. It is said to always give birth to twins. Of these twins, it hates one, but loves the other, just as the callitrix, cericopithicus and cynocephalus apes of medieval bestiaries. The ape is also described as lively and has a pleasant...

apes of medieval bestiaries are described to.
The callitrix apes are said to have long beards and wide tails.