(c) _The Interradial Funnels or Funnel Cavities._ It will be seen at once that the four suspensoria serve as partitions to divide the upper portion of the bell cavity, the part that lies between the stomach and the lateral walls of the subumbrella, into four compartments. These compartments extend upwards in the four interradii like inverted funnels, whence their name. In the series of cross-sections they can be traced upwards with constantly diminishing area from the level of the suspensoria, Fig. 10 (_if_), to Fig. 6, which is taken very near the top of the bell. Homologous structures exist in all the Scyphomedusæ, and in some of the Lucernaridæ they are continued up even into the stalk of the attached jelly-fish.
(d) _The Velarium._ Charybdea, like most of the Cubomedusæ, possesses a velum-like structure around the opening of the bell cavity (Fig. 3, _v_). The velarium is a thin muscular diaphragm, resembling the true velum in position and essential structures, but differing from the velum in its origin, and in the possession of diverticula from the gastro-vascular system, the velar canals. Of these there are in C. Xaymacana very regularly sixteen, four in each quadrant. Their outline is seen in Fig. 3 to be forked with small irregular accessory processes. As for its origin, the velarium of the Cubomedusæ is commonly accounted to have arisen by fusion of marginal lobes, as in the case of the velarium of the Discomedusæ. Pending decisive ontological evidence, the slight notches in the four perradii seen in Fig. 3 may perhaps be taken as slight indications of a primitive unfused condition, but the question will be brought up again when the vascular lamellæ are discussed.
(e) _The Frenula._ Just as the stomach is attached to the walls of the subumbrella in the four perradii by the suspensoria, so in the lower part of the bell cavity the velarium is attached to the wall of the subumbrella in the perradii by four structures similar to the suspensoria, the frenula velarii. The frenula, like the suspensoria, resemble the brackets of a shelf, with the difference that in the case of the frenula the bracket is above the shelf, their purpose being evidently to keep the velarium stiff against the outflow of water produced by the pulsations of the bell. According to the greater need of strength in this case, we find the frenula stouter, more buttress-like than the suspensoria. The gelatinous ridge that gives them the necessary firmness is thickened so as to be triangular in section, as shown in Fig. 16 (_frn_).