2. _Form of Bell._ C. Xaymacana shows the typical division of the external surface into four almost vertical perradial areas (Figs. 1-3, _p_), separated by four stoutly arched interradial ribs or bands (Figs. 1-3, _i_). These ribs thus play the part of corners to the Cubomedusan pyramid. They are formed by the thickenings of the jelly of the exumbrella, and serve to give the necessary strength to the four interradial corners, each of which bears one of the four tentacles at its base. Each rib is further divided into two longitudinal strips by a vertical furrow lying exactly in the interradius (Fig. 2, _ifr_). The surface of the exumbrella is thus marked by twelve longitudinal furrows, as seen in the same figure (2). Of these, four are the interradial furrows just mentioned; the other eight are the adradial (_afr_) furrows, which set off the four perradial surfaces of the pyramid from the four interradial ribs or bands of the corners, each of which is again subdivided, as mentioned above, by the shallower interradial furrows. Each interradial furrow ends above the base of the corresponding pedalium, at about the level of the sensory club; each adradial furrow diverges toward the perradius in the lower third of its course, and thus with its companion furrow narrows down the perradial surface of the pyramid in the lower part of the bell to an area of not much greater width than the niches in which the sensory clubs lie. The projecting interradial corners are of course correspondingly enlarged in the lower part of the bell, and in this way the contours of the surface are changed from those figured in the view of the bell from above (Fig. 2) to those of Fig. 3, which represents a view of the bell margin from below. 3. _Pedalia._ From the base of the interradial corner bands spring the four pedalia (Fig. 1, _pe_), gelatinous appendages of the margin having much the same shape as the blade of a scalpel. These in turn bear on their distal ends, as direct continuations, the long, contractile, simple tentacles. The relatively stiff pedalia have the same relation to the flexible tentacles that a driver’s whip-stock has to the long lash. In the living animal the pedalia are found attached to the margin at an angle of about 45° with the longitudinal axis of the bell. In the preserved specimens they are bent in toward the axis by the contraction of the strong muscles at their base, in which position they are figured by Claus for C. marsupialis (’78, Taf. I., Figs. 1 and 2).