Hyginus Gromaticus (Gromaticus from groma, a surveying device) was a Latin writer on land-surveying, who flourished in the reign of Trajan (AD 98–117). Fragments of a work on legal boundaries attributed to him will be found in C. F. Lachmann, Gromatici Veteres, i (1848)  and in Carl Olof Thulin, Corpus agrimensorum Romanorum, I Opuscula agrimensorum veterum, Leipzig 1913. The 'surname' Gromaticus was falsely attributed to Hyginus: There is only one reading in the manuscripts (Arcerianus A 161) which ascribes the work to a KYGYNVS GROMATICVS. The other mss. give the work the title LIBER HYGINI GROMATICVS, so undoubtedly the book was called Liber gromaticus.
A treatise on Roman military camps (De Munitionibus Castrorum), was formerly attributed to him, but is probably of later date, about the 3rd century AD (ed. W. Gemoll, 1879; A. von Domaszewski, 1887) and is now attributed to "Pseudo-Hyginus".