Limitanei and Pseudocomitatenses
Limitanei (from the word limes, meaning the frontier of the Empire) were soldiers garrisoned along the borders of the Empire. They were considered of a lower rank than the Comitatenses, who composed the field army, and the Palatini (see this post for a definition of that term) or elite.
Limitanei included legionary and auxiliary units.
The role of these frontier units was to patrol the borders and prevent raiders to enter into the empire. In case of a large scale attack, the field army would be engaged.
Some units of Limitanei have probably been incorporated in the field army under the name of Pseudocomitatenses, but remained the less considered... and less paid!
Identifying my unit
When I painted the soldiers pictured below, I first considered them as Auxilia Palatina. Their shield pattern was simply the one displayed on the Hät Medium infantry set, and frequently seen in various illustrations. But I couldn't give the unit a name, because that pattern is not shown in the Notitia Dignitatum. We know that the Notitia Dignitatum doesn't display shield patterns for all the units mentioned. For instance, none of the Limitanei units have their shields illustrated, and we also know that some Pseudocomitatenses are also missing.
The pattern that I was looking for can be seen on a famous Roman mosaic from the 4th century AD in Piazza Armerina in Sicily (see below). That mosaic represents a hunt scene. The hunters are trying to catch African animals, probably for the venationes (animal hunt) in an amphitheatre.
So it may be that my unit is an African Limitanei or Pseudocomitatenses unit. Since the figures are not heavily equipped, I will base them as Auxilia for DBA.
Here are the figures:
I painted two Auxilia elements, supported by one Psiloi element. All figures by Hät.
I would be very curious to know if anyone has a better idea for the identification of this shield pattern. If so, please don't hesitate to give your point of view, that's one of the reasons why we share all this on the web :) All comments welcome.