Cephalon: semicircular to subtriangular, typically with gonatoparian sutures (a few opisthoparian, e.g., Bathycheilidae, primitive Homalonotidae); glabella narrowing forwards; eyes holochroal, often small; hypostome conterminant, rostral plate present.
Thorax: 11 – 13 (typically 13), segments with rounded tips.
Pygidium: semicircular or triangular, without spinose margin.
Superfamilies/Families: Calymenoidea/Bathycheilidae, Bavarillidae, Calymenidae, Pharostomatidae, Homalonotidae
Representative Genera: Bathycheilus, Bavarilla, Calymene, Diacalymene, Flexicalymene, Plaesiacomia, Parahomalonotus, Homalonotus, Trimerus.

Reedops

 

Calymene

Cheirurus