Here are a few more mentions of Buddhism etc from the writings of the Early
Church Fathers:
St Jerome in "Against Jovinianus" (393CE) states, in defending the doctrine
of Christ's virgin birth that "It is handed down among the Gymnosophists of
India that Buddha, the founder of their system, was brought forth by a
Virgin from her side."
Hyppolitus in his "Refutation of All Heresies" states that "Democritus, son
of Damasippus, a native of Abdera, conferring with many gymnosophists among
the Indians, and with priests in Egypt, and with astrologers and magi in
Babylon, propounded his system."
Elsewhere in his book, Hyppolitus deals with the Encratites, a group which
was considered to be heretical because they were vegetarian, drinkers of
water only and celibate. He states that their views derive in part from
the Gymnosophists of India.
Hyppolitus also has an interesting section in his book giving an account of
the beliefs and life-style of Brahmin ascetics
However, there seems to be a lack of clarity about the so-called
Gymnosophists. At times they seem to have been identified with Buddhists
but otherwise the name seems to have been used as a general term for Indian
ascetics. Those whose Greek is a bit rusty may need to be reminded that the
"gymno" in "gymnosophists" means "naked". If these ascetics were indeed
naked, then one immediately thinks, in an Indian context of some Jains and
not Buddhists.