Kieffer, 1913
Body
Medium sized larvae up to 10 mm long (Moller Pillot, 1984b). Living larvae are brownish, yellowish or greenish. The L4 setae of the abdomen are short and simpel. The anterior and posterior parapods, 4 anal tubules and procercus are present.
Head
The head length is up to 0.9 mm (Moller Pillot, 1984b). Brillia modesta has a large dark oval spot on the ventral side of the headcapsule Bril mod head ventral.
Antenna
The antenna consists of four segments. The second segment is divided in a short proximal part and a long distal part Bril antenna. The blade is subequal to the flagellum and the Lauterborn organs are distinct and situated on the apex of the second antennal segment.
Mentum
The mentum has two large median and 5 pairs of lateral teeth. Between the median teeth usually a small toothlet is present Bril flavifrons mentum Bril mod mentum. The ventromental plates are weak and the beard is absent.
Labrum
The pecten epipharyngis consists of three scales, SI is plumose or divided and the premandible with two indistinct apical teeth (Wiederholm, 1983).
Mandible
The mandible with a distal tooth and 4 smaller teeth within. Seta interna with serrate or plumose branches (Wiederholm, 1983).
Differential characteristics
The divided second antennal segment Bril antenna separates Brillia from the other Orthocladiinae except from Heleniella which has a much shorter head (0.27 versus 0.55 in Brillia (Moller Pillot, 1984b)). IdentifyIt also separates Brillia from the other Orthocladiinae by the combination of two median mentum teeth Bril flavifrons mentum, 4 segmented antenna, weak ventromental plate and a SI which is not simpel. Brillia shares the first three characters with Eukiefferiella, which has a simpel SI.
Diversity
European species: 2
Treated species:
Brillia flavifrons
Brillia modesta