Cūlanāga Thera 

Also referred to as Tipiṭaka-Cūlanāga, he was apparently a very well-known commentator since his opinions are quoted in the commentaries of Buddhaghoṣa. He was a pupil of Summa Thera of the Dīpavihāra, a Sri Lankan monastery, with whom he does not always seem to have agreed in his interpretations of various matters. Although often cited as an authority, it is not known whether Cūlanāga ever wrote anything himself.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)