M. Damatius U., author of a (4th-cent. AD) commentary on the poems of Vergilius, which deals with earlier commentators (Cornutus , Velius  Longus) and - in addition to Carminius and Donatus  - constitutes the foundation of Servius's  commentary; its influence on Servius is likely to have exceeded the 11 quotations that survive.
S. Timpanaro, Per la storia della filologia virgiliana antica, 1986, 129-134
R. Kaster, Guardians of Language, 1988, 438
P. L. Schmidt, in: HLL 5, § 526.3.