. Natural history. Zoology. Fig 7.—Lepeaih Pal- LASIANA (magnified). the presence of the horny lid covering the tentacle sheath. A second order, the Cyclostomata (circular-mouthed), commonly form white circular or fan- shaped stony crusts, plates, or branches, the component cells being tubular, and without horny lids. The tubes are frequently arranged in single or double rows. In a third order, the Ctenostomata (comb - mouthed), the colonies are horny or fleshy, never stony. When the tentacles are extruded, a comb-like circle of fine bristles is seen arising from the pro- boscis near the base
. Natural history. Zoology. Fig 7.—Lepeaih Pal- LASIANA (magnified). the presence of the horny lid covering the tentacle sheath. A second order, the Cyclostomata (circular-mouthed), commonly form white circular or fan- shaped stony crusts, plates, or branches, the component cells being tubular, and without horny lids. The tubes are frequently arranged in single or double rows. In a third order, the Ctenostomata (comb - mouthed), the colonies are horny or fleshy, never stony. When the tentacles are extruded, a comb-like circle of fine bristles is seen arising from the pro- boscis near the base of the tentacles; when the tentacles are retracted the bristles form a kind of operculum. The gelatinous Alcyonidium, so called from its resemblance to the zoophyte Alcyonium ("dead men's fingers"), forms fleshy masses or long cylindrical branches. The polyps, which are em- b dded near the surface, extrude their tentacles when undisturbed. The Nit Coralline (Amathia lendigera) forma little dark brown bushy tufta, the ce'la being arranged on the branches in double rows of small horny cylinders like Pan's-pipes. The three orders above mentioned are included in one group, the Infundibulata (infimdibidum, a funnel), in which the tentacles form a funnel-like circle round the mouth. The rest of the Bryozoa are included under the group Lophopoda (crest foot), in which the tentacles are arranged in a horse-shoe shaped zone round the mouth. Nearly all the fresh-water Bryozoa belong to this group. Lophopiis crystalUmis (Figs. 8, 9) is found in the form of little jelly-like blobs on the stems of Duck-weed (Fig. 8). The polypides can be seen aa yellowish red streaks in the interior of a blob; when the horae-shoe plumes of tantacles are expanded the animal presents a beautiful appearance. Lophopiia and other fresh-water Bryozoa commonly propagate them- selves by means of peculiar internal buds, termed "stato- blasts " (Fig. 10), which arise in the cord passing from the
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Keywords: ., bookauthorly, bookcentury1800, bookdecade1890, booksubjectzoology
