Illaenus

Illaenus is a genus of trilobites from Russia and Morocco, from the middle Ordovician.
Species included in this genus can reach a length of about . They are without glabella and without articulation of the tail. The cephalon has a high profile and recurved genal spines. Eyes are distant from the axis of the head, situated nearer to the edge.
Selected species.
This genus includes about 50 species: