The brain, the compound eyes and the ocelli are described for some zygentomid species. Special interest has been focused on Tricholepidion gertschii, a newly discovered, primitive species. The brain morphology shows great similarities in the general shape and in details within the whole suborder. The compound eyes of Tricholepidion gertschii and Lepisma saccharina resemble each other closely. The present investigation has shown that the zygentomid and pterygote compound eyes are similar in that there are no corneagen cells. The view that the compound eyes of the Zygentoma should constitute a connecting link between crustacean and insect compound eyes can no longer be maintained. Tricholepidion gertschii possesses three ocelli. Their structure stresses the connection between thysanurans and pterygote insects. In this connexion the homology of reduced ocelli is discussed and their nerve contacts reinvestigated.