De Man published his fourth note regarding nematodes of the North Sea and Channel in 1890. In that article he gave additional descriptions of five species, previously described by Bastian from the South English Coast: Comesoma vulgare (a common species of the North Sea and Mediterranean); Spira parasitifera (nowadays known as Spirinia parasitifera, a cosmopolite); Chromadora filiformis (nowadays is Chromadorella, cosmopolite); Cyatholamus punctatus (nowadays in Praeacanthonchus, a North Sea species); Oncholaimus glaber (now known as Viscosia glabra) and Oncholaimus viscosus (nowadays Viscosia viscosa, a common North Sea species).
The genus Oncholaimus has since his erection been split in a number of new genera. De Man erected the new genus Oncholaimellus in which he placed his new species Oncholaimellus calvadosicus. In his article he still described three new North Sea species: Monohystera normandica (now Cylindrotheristus normandicus), Spilophora tentabunda (nowadays Innocuonema tentabundum) and Oncholaimus langrunensis (now in Viscosia).
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