What is an order of Siphonophora, furnished with an air sac, or float, and a series of nectocalyces. See Illust. under Nectocalyx called?

physophorae — An order of Siphonophora, furnished with an air sac, or float, and a series of nectocalyces. See Illust. under Nectocalyx. (Webster's 1913.)

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