• Webster's Revised Unabridged Dictionary
    • n Somatocyst (Zoöl) A cavity in the primary nectocalyx of certain Siphonophora. See Illust. under Nectocalyx.
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Century Dictionary and Cyclopedia
    • n somatocyst The inflated stem or body of some siphonophorans, or oceanic hydrozoans, serving as a pneumatocyst or air-sac to float or buoy these organisms, as in the case of the Portuguese man-of-war. See Calycophora, Siphonophora, and cuts under Diphyidæ and Physalia.
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Webster's Revised Unabridged Dictionary
Gr. sw^ma sw`matos, body + ky`stis a bladder