. Zoology : for students and general readers . Zoology. Fig. 142.—Larra or "Pilidium" of Nemer- „f j--|,„ flnf wnrm i<? indi- tes, with tlie worm growing in it. v, velum ; "I ^'^^ ^^^ WOrm IS mUI After Leuc'kart*"°''°"'''^''''*°"°™'~ cated, and appears some- what as in Fig. 143. The yolk mass, with the alimentary canal of the Pilidium, is taken bodily into the interior of the Nemertes, the Pilidium-skin falls off, and the worm finally seeks the bottom. The free-swimming larvEe of other ISTemerteans are very closely similar to those of the Annelids, so that from


. Zoology : for students and general readers . Zoology. Fig. 142.—Larra or "Pilidium" of Nemer- „f j--|,„ flnf wnrm i<? indi- tes, with tlie worm growing in it. v, velum ; "I ^'^^ ^^^ WOrm IS mUI After Leuc'kart*"°''°"'''^''''*°"°™'~ cated, and appears some- what as in Fig. 143. The yolk mass, with the alimentary canal of the Pilidium, is taken bodily into the interior of the Nemertes, the Pilidium-skin falls off, and the worm finally seeks the bottom. The free-swimming larvEe of other ISTemerteans are very closely similar to those of the Annelids, so that from this fact and the nature of the highly developed circulatory system, the Nemerteans have been removed from the neighborhood of the flat worms, and placed near the Balanoglossus and Gephyrea, as Avell as the leeches. Order 1. Anojjla.—In this group the pro- lloTttmI^ie±'"' l^oscis is without a style. The species of Lineus and ileckelia are, in some cases, very long. Meulcelia ingens Leidy is 2^ centimetres (an inch) wide, and attains a length of 4 metres (ISj feet). It. Fig. 143. — Tetra-. 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 Packard, A. S. (Alpheus Spring), 1839-1905. New York : Henry Holt


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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1879