Frustules globose, ellipsoidal or cylindrical, concatenate, closely joined together.
Here it is usually enclosed in the cephalis and is spherical, ellipsoidal or spheroidal, often flattened almost into a disc.
Thus the cell outline is clearly marked, the nucleus large and spherical or ellipsoidal.
This species being observed alive, showed a transparent central capsule of ellipsoidal form, two-thirds as large as the shell.
Ovoid or ellipsoidal branchlets or receptacles, single or in groups, occur at intervals along the sides of both stem and branches.
Shell composed of four concentric shells, two ellipsoidal cortical shells, and two spherical medullary shells.
Finally the nuclear disc assumes an ellipsoidal form and becomes the nuclear body.
Medullary shell (fig. 9) half as large as the cortical, ellipsoidal and papillate, with regular, circular pores.
Shell composed of two ellipsoidal, cortical, and two spherical medullary shells.
Small animals with ellipsoidal form and about twice as long as broad.