Summary: Data on the contents of individual rare earths are summarized for 24 members of the aeschynite-priorite series and 3 lyndochites. It is shown that the data are in accord with the assignment of lyndochite to the aeschynite-priorite series. The available X-ray data are not definitive, but indicate at least strong similarity of lyndochite to aeschynite ; the classification of lyndochite as a variety of euxenite is excluded.