Extant works known as Ars grammatica have been written by
Donatus's Ars Major is only a little longer, but on a much more elevated plane. It is a list of stylistic faults and graces, including tropes such as metaphor, synecdoche, allegory, and sarcasm. Donatus also includes schemes such as zeugma and anaphora.
The Ars grammatica or De Oratione et Partibus Orationis et Vario Genere Metrorum libri III by Diomedes is a Latin grammatical treatise. Diomedes wrote probably in the late 300s CE. The treatise is dedicated to a certain Athanasius.
The third book on poetry is particularly valuable, containing extracts from Suetonius's De poetica. This book contains one of the most complete lists of types of dactylic hexameters in antiquity, including the teres versus, which may (or may not) be the so-called "golden line."
The Ars of Diomedes still exists in a complete form (although probably abridged). It was first published in a collection of Latin Grammarians printed at Venice by Nic. Jenson, about 1476. The best edition of Diomedes's Ars Grammatica is in H. Keil's Grammatici Latini, vol I.