The work of the steamship »Siboga” among the islands of the East Indian Archipelago resulted in the discovery of many new species of unstalked crinoids. In view of the large amount of work necessary in assembling and digesting the data accumulated on these, and especially on the species already known, it has seemed advisable to publish in advance preliminary diagnoses of the new forms in order to guard against possible anticipation. In the present paper the new species belonging to the families ANTEDONIDAE and ATELECRINIDAE, including among them the most striking of those collected by the »Siboga”, are considered. All of the new species will be described in greater detail and figured in the final memoir on these animals in the »Siboga” series 1).