The apparent axis or basal support of the scorpion's lung-books shown in the figures, is a false or secondary axis and merely a part of the infolded surface which forms the air-chamber.
ridges, which are usually prolonged as teeth beyond the infolded margin.
In certain genera the margins are infolded either along their whole length (the male of Schistostomum haematobium; fig.
In addition to these suckers the sides of the anterior region may become infolded and give rise to an accessory adhesive organ (Holostomidae).
Tentacles infolded, during retraction, into a vestibule which can.