Figs. 40-43. Horizontal sections through the base of a pedalium at successive levels, w-x-y-z, Fig. 5, to show marginal lamella.
Fig. 44. Diagram to show relations of sensory niche, of bell margin and velarium in adult Tripedalia. The velarium represented as pendant.
Fig. 45. To show the same structure in a young Tripedalia.
Fig. 46. Horizontal section through the last just at the margin, to compare with Fig. 29.
Fig. 47. Cross-section through the nerve ring.
Fig. 48. The structure of the nerve as seen by focusing at successive levels.
Fig. 49. Diagram to show the relation of the nerve ring to the sensory club.
Fig. 50. Horizontal section through the upper part of the sensory niche, to show passage of nerve root through gelatine of subumbrella to stalk of sensory club.
Fig. 51. Vertical section through base of stalk of sensory club, to show same passage.