Saguinus

Japanese: Saguinus

…The classification of the family Marmoset varies among scholars, with between 2 and 5 genera and 20 to 30 species. It includes the marmosets, tamarins , and lion tamarins , and sometimes includes the Guerde monkeys as a subfamily. Marmoset monkeys are generally small, with head and body lengths of around 20 cm, and do not look very monkey-like in appearance.

From [Tamarin]

…the name of the New World monkeys belonging to the genus Saguinus in the family Marmoset, order Primates. The group commonly called tamarins is divided into one or two genera by scholars, and together with the group of marmosets, they form the family Marmoset.

*Some of the terminology explanations that mention "Saguinus" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…キヌザル科の分類は2～5属，20～30種と学者によってさまざまである。マーモセット属，タマリン属Saguinus，ライオンタマリン属Leontopithecusなどが含まれ，ゲルディモンキーを亜科のレベルで含めることもある。　キヌザルの仲間は一般に小型で頭胴長20cmくらいのものが多く，外見上あまりサルらしくない。…