Published online by Cambridge University Press: 11 May 2009
It is generally assumed that there are two species of the genus Podocoryne, in northern waters, in which free swimming medusae are produced, P. carnea M. Sars and P. areolata Alder. Of these, the hydroid of P. carnea is known for certain, and that of P. areolata is thought to be the hydroid described by Alder under that specific name. Recently, I have found that there are two more species of Podocoryne medusae in British waters, P. hartlaubi Neppi & Stiasny and P. minima (Trinci). There are, therefore, two more hydroids to be found and it will be shown that the identity of the hydroid of the so-called medusa P. areolata must remain in doubt.