A, zooecium of _Victorella pavida_, Kent, with the polypide retracted (after Kraepelin). B, zooecium of _Hislopia lacustris_, Carter (typical form from the United Provinces), with the collar completely and the tentacles partly protruded. A=collar; B=orifice; C=tentacles; D=pharynx; E=oesophagus proper; F=gizzard; G=stomach; G'=cardiac portion of stomach; H=intestine; J=rectum; K=anus; L=young egg; M=green cysts in gizzard; N=testes; O=ovary; O'=funiculus. The muscles are omitted except in fig. B.] Family PALUDICELLIDÆ. PALUDICELLIDÆ, Allman, Mon. Fresh-Water Polyzoa, p. 113 (1857). HOMODIÆTIDÆ, Kent, Q. J. Micr. Sci. x, p. 35 (1870). VICTORELLIDÆ, Hincks, Brit. Marine Polyzoa, p. 558 (1880). PALUDICELLIDÉES, Jullien, Bull. Soc. zool. France, x, p. 174 (1885). PALUDICELLIDES, Loppens, Ann. Biol. lacustre, iii, p. 170 (1908). VICTORELLIDES, _id._, _ibid._ p. 171. _Zoarium._ The zoarium is recumbent or erect, and is formed typically either of zooecia arising directly in cruciform formation from one another, or of zooecia joined together in similar formation with the intervention of tubules arising from their own bases. Complications often arise, however, either on account of the suppression of the lateral buds of a zooecium, so that the formation becomes linear instead of cruciform, or by the production in an irregular manner of additional tubules and buds from the upper part of the zooecia. A confused and tangled zoarium may thus be formed, the true nature of which can only be recognized by the examination of its terminal parts. _Zooecia._ The zooecia are tubular and have a terminal or subterminal orifice, which is angulate or subangulate as seen from above. Owing to this fact, to the stiff nature of the external ectocyst, to the action of circular muscles that surround the tentacular sheath, and to the cylindrical form of the soft inverted part, the orifice, as seen from above, appears to form four flaps or valves, thus [illustration: sketch, similar to a cloverleaf inside a square with rounded corners]. _Polypide._ The alimentary canal is elongate and slender as a whole, the oesophagus (including the pharynx) being of considerable length. In _Paludicella_ and _Pottsiella_ the oesophagus opens directly into the cardiac limb of the stomach, which is distinctly constricted at its base; but in _Victorella_ the base of the oesophagus is constricted off from the remainder to form an elongate oval sac the walls of which are lined with a delicate structureless membrane. _Victorella_ may therefore be said to possess a gizzard, but the structure that must be so designated has not the function (that of crushing food) commonly associated with the name, acting merely as a chamber for the retention of solid particles. In this genus the cardiac limb of the stomach is produced and vertical but not constricted at the base. The tentacles in most species number 8, but in _Paludicella_ there are 16.