Hydroid and young medusa stages of Dipurena strangulata (Hydrozoa, Corynidae)

The hydroid stage in the life history of Dipurena strangulata, a relatively well-known medusa along the United States east coast, is described for the first time. A previous description of the young medusa does not accord with observations recorded here, but is similar to and may have been based on young Linvillea agassizi rather than D. strangulata. Of the described hydroids of Dipurena, D. strangulata is most like D. reesi morphologically, but differs in the position of the filiform tentacles and the number of endodermal cells in the capitate tentacles. The status of the various species of Dipurena described from the North American Atlantic coast is reviewed.