ABSTRACT
Sclerite associations of the body wall in almost completely preserved fossil holothurians (Middle Devonian “Mortensenltes”, Eocaudina; Lower Jurassic Calclamna and Binoculites) are principally comparable to those cemented as aggregates which are found by micropalaeontological sieving. Aggregates, therefore, generally could be interpreted as representative parts of complete specimens; and consequently, if treated as natural species, they might prove as a most valuable tool for phylogenetic considerations.
