. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. IIVDROZOA—SIPIIOXOPilOB A. 245 possess a circle of tentacles. They always, however, have a long tentacle arising from their base. This tentacle can be extended to a considerable length, and be retracted into a spiral coil. It rarely has a simple form, but, as a rule, it bears a number of unbranched lateral twigs, which are also very contrac- tile. These tentacles are invariably beset with a great number of nema- tocysts, which in many places are closely packed and have a regular arrangement
. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. IIVDROZOA—SIPIIOXOPilOB A. 245 possess a circle of tentacles. They always, however, have a long tentacle arising from their base. This tentacle can be extended to a considerable length, and be retracted into a spiral coil. It rarely has a simple form, but, as a rule, it bears a number of unbranched lateral twigs, which are also very contrac- tile. These tentacles are invariably beset with a great number of nema- tocysts, which in many places are closely packed and have a regular arrangement. These aggregations of thread-cells are especially found on the lateral branches of the tentacles, and give rise to large, brightly-coloured swellings, the batteries of nematocysts. The batteries show considerable variations. Fis. 187.— Group of buds of aPhysophor at the bottom of the pneuma'.ophore. C, Central cavity ; S/c, nectocalyx bud with the ectoclermal ingrowth. (t. 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 Claus, Carl, 1835-1899; Sedgwick, Adam, 1854-1913; Sinclair, F. G. (Frederick Granville), b. 1858. London, Swan Sonnenschein & co.
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Keywords: ., book, bookcentury1800, bookcollectionbiodiversity, bookdecade1890
