. A text-book of invertebrate morphology. Invertebrates. TYPE PE080P70IA. 2&d phic form is known as the Vibracula, and consists of a slender filament movably articulated to a rounded structure corre- sponding to the head of the Avicularia ; the filaments wave continually to and fro and are probably tactile in function. In many forms, too, in the neighborhood of the mouths of the ordinary individuals sac-like pouches occur, in which the ova undergo their development. These structures, known as ovicdls (Fig. 116, oc), or oaecia, have also been considered modi- fied individuals, but seem rath
. A text-book of invertebrate morphology. Invertebrates. TYPE PE080P70IA. 2&d phic form is known as the Vibracula, and consists of a slender filament movably articulated to a rounded structure corre- sponding to the head of the Avicularia ; the filaments wave continually to and fro and are probably tactile in function. In many forms, too, in the neighborhood of the mouths of the ordinary individuals sac-like pouches occur, in which the ova undergo their development. These structures, known as ovicdls (Fig. 116, oc), or oaecia, have also been considered modi- fied individuals, but seem rather to be organs of the ordinary individuals, arising as a pouching of their walls. Finally, not infrequently certain individuals relinquish their nutritive. Fig. 117.—A, Lauva op Pedicellina (after Hatschek) ; B, Cyplionautes (after Prouho). ad = adhesive organ. « = stomach. cal = calotte. sh = shell. cor = corona. pyr = pyriform organ.' function and serve as root-like anchors or stem-like supports for the entire colony. As regards the internal structure of the Gymnolsemata it is unnecessary to add anything to what has already been stated in describing the general characteristics of the order Ectoprocta. Development of the Polyzoa.—The larva of Pedicellina (Fig. 117, A ), which may be taken as a type of the Endoprocta, is a somewhat dome-shaped organism, the summit of the dome being occupied by an apical thickening [caT) bearing a tuft of cilia, while at the margin there is a stout ciliary band, the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original McMurrich, J. Playfair (James Playfair), 1859-1939. New York, H. Holt and Company
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