of Terebelliformia, [252];
absence of, in certain Polychaeta, [253];
of Oligochaeta, [355];
of Leeches, [396];
of Gephyrea, [415], [436], [447];
of Phoronis, [455]
Vaucheria, Rotifers in, [227]
Vejdovsky, on Rhabdocoels, [46];
of Terebelliformia, [252];
absence of, in certain Polychaeta, [253];
of Oligochaeta, [355];
of Leeches, [396];
of Gephyrea, [415], [436], [447];
of Phoronis, [455]
Vaucheria, Rotifers in, [227]
Vejdovsky, on Rhabdocoels, [46];