What is "asaphus"

Asaphus \As"a*phus\, n. [NL., fr. Gr. ? indistinct, uncertain.] (Paleon.) A genus of trilobites found in the Lower Silurian formation. See Illust. in Append. [1913 Webster] ||

Asaphus is a genus of trilobites, that is known from the Lower (upper Arenig) and Middle Ordovician of northwestern Europe (Sweden, Estonia, Saint Petersburg Area).