As a rule, the wall of the ovary is continued into a uterine tube opening into the cloaca; but in Philodinaceae this is absent, and the young are free in the body cavity and escape by perforating the cloacal walls.
The apical end of the rotifer usually narrows suddenly beyond the curve of the gut and the cloacal aperture to form the foot of pseudopodium which ends in an organ of attachment, a pair of movable toes, each with the opening of a cement-gland (gl) at its tip. Thus for orientation we place the rotifer like the cuttle-fish, head downwards: the ciliated disk is basal or oral, proximal to the rest of the animal, the foot is apical, and the brain and cloacal aperture are anterodorsal.
The mouth and cloacal aperture are generally at opposite ends of the ventral surface.
Open into a cloacal slit on the surface of the body.
Slender, tapering behind, with subventral cloacal orifice; thin cuticle without papillae; flattened spicules; no gills.
Into this same cloacal chamber open ventrally a pair of ciliated tubes communicating by funnels with the coelom (Nansen and Wheeler); these are possibly nephridia, and excretory in function.
Short, truncate in front and behind; cloacal orifice transverse; gills present; rather thin cuticle; no radula.
Cl, Cloacal or pallial chamber of Neomeniae and Chaetoderma.
Little thicker than the an terior; the posterior ex tremity forms the enlarged funnel-like branchial or cloacal chamber.
This arrangement facilitates the internal fecundation of the female without copulation, the female absorbs the spermatozoa by squeezing them out of the spermatophore between the cloacal lips.