1911 Encyclopædia Britannica/Gephyrea

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GEPHYREA, the name used for several groups of worm-like animals with certain resemblances but of doubtful affinity. In the article “Annelida” in the 9th edition of this Encyclopaedia, W. C. McIntosh followed the accepted view in associating in this group the Echiuridae, Sipunculidae and Priapulidae. E. Ray Lankester, in the preface to the English translation of C. Gegenbaur’s Comparative Anatomy (1878), added the Phoronidae to these forms. Afterwards the same author (article “Zoology,” Ency. Brit., 9th ed.) recognized that the Phoronidae had other affinities, and placed the other “gephyreans” in association with the Polyzoa as the two classes of a phylum Podaxonia. In the present state of knowledge the old group Gephyrea is broken up into Echiuroidea (q.v.) or Gephyrea armata, which are certainly Annelids; the Sipunculoidea (q.v.) or Gephyrea achaeta, an independent group, certainly coelomate, but of doubtful affinity; the Priapuloidea (q.v.), equally of doubtful affinity; and the Phoronidea (q.v.), which are almost certainly Hemichordata.