. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. FRONT VIEW SIDE VIEW stem- cauline nematothecae. hydrocladium apophysis ORIGIN OF HYDROCLADIUM Fig. 106. Plumulariidae: position of nematothecae. opening may be duplicated and its distal end may be drawn out into a long tube reaching well beyond the hydrothecal margin. In most of the Halopterinae the laterals (or the first pair of laterals if two are present) are seated on long pedicels fused to the side-walls of the hydrotheca. In addition to those associated with the hydrothecae, nematothecae may o
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. FRONT VIEW SIDE VIEW stem- cauline nematothecae. hydrocladium apophysis ORIGIN OF HYDROCLADIUM Fig. 106. Plumulariidae: position of nematothecae. opening may be duplicated and its distal end may be drawn out into a long tube reaching well beyond the hydrothecal margin. In most of the Halopterinae the laterals (or the first pair of laterals if two are present) are seated on long pedicels fused to the side-walls of the hydrotheca. In addition to those associated with the hydrothecae, nematothecae may occur on athecate stems or internodes, on the peripheral tubes of fascicled stems, on the hydrorhiza and on the gonothecae or other reproductive bodies. Nematothecae may provide useful characters for specific diagnosis, but it must be borne in mind that they are easily lost in dredged and preserved material. A structure of doubtful function, the mamelon, is characteristic of many Plumulariinae. It is a small nipple-like protuberance bearing a terminal opening and is seated on the upper surface of the hydrocladia-bearing apophysis of the stem. Its aperture communicates with the cavity between the perisarc and coenosarc. It possibly contains a nematophore in life, or it may be concerned with the hydrostatic pressures of the colony. In the few cases of hydroids para- sitic on Plumulariidae ( Hebella furax) the parasitic hydrorhiza appears to. 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 South African Museum. Cape Town : The Museum
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
