सिलेंटर्स लेने वाले दो रूपों में से एक: यह एक संगठित के जीवन चक्र में मुक्त तैराकी यौन चरण है; इस चरण में इसमें एक जिलेटिनस छतरी के आकार का शरीर और तम्बू है

medusan's Usage Examples:

There remains only the third feature, the endodermal gonads, as an argument for uniting the Scyphomedusae with the Anthozoa, against which must be set all the peculiarities of medusan organization in which the Scyphomedusae resemble the Hydromedusae.

I), proving its medusan nature beyond all doubt.

Thus a bract may be regarded, with Haeckel, as a modified umbrella of a medusa, a siphon as its manubrium, and a tentacle as representing a medusan tentacle shifted in attachment from the margin to the sub-umbrella; or a siphon may be compared with a polyp, of which the single tentacle has become shifted so as to be attached to the coenosarc and so on.

As in the Gymnoblastea, the difficulty of uniting the hydroid and medusan systems into one scheme of classification is very great in the present state of our knowledge.

Another medusan genus is Proboscidactyla.

50) are medusan genera.

Amphinema is a medusan genus of unknown hydroid.

Secondly, there is the evidence from the development, namely, the presence of the entocodon in the medusa-bud, a structure which, as explained above, can only be accounted for satisfactorily by derivation from a medusan type of organization.

The evidence against this view may be classed under two heads: first, comparative evidence; hydroids very different in their structural characters and widely separate in the systematic classification of these organisms may produce medusae very similar, at least so far as the essential features of medusan organization are concerned; on the other hydroids closely allied, perhaps almost indistinguishable, may produce gonophores in the one case, medusae in the other; for example, Hydractinia (gonophores) and Podocoryne (medusae), Tubularia (gonophores) and Ectopleura (medusae), Coryne (gonophores) and Syncoryne (medusae),-and so on.

Cladonema still has the typical medusan structure, and is able to swim about, but in Clavatella the umbrella is so much reduced that swimming is no longer possible.

medusan's Meaning':

one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles