Taxonomic descriptions of some conspicuous species in the family Strombidiidae (Ciliophora: Oligotrichida) from the Isles of Shoals, Gulf of Maine

Ten species of marine strombidiid ciliates were identified after protargol staining plankton samples. The taxonomic redescriptions include a diagnosis forTontonia gracillimaFaure-Fremiet, 1924,Strombidium wulffi(Wulff, 1919) Kahl, 1932,Strombidium acutumLeegaard, 1915,Strombidium constrictum(Meunier, 1910) Wulff, 1919,Strombidium compressum(Leegaard, 1915) Kahl, 1932, andStrombidium sulcatumClaparede & Lachmann, 1858. Four new species,Strombidium dalumn.sp.,Strombidium epidemumn.sp.,Strombidium rhynchumn.sp., andStrombidium tressumn.sp., are defined based primarily on the characteristics of the anterior oral polykinetids, numbers of oral polykinetids, and presence of anterior protuberance.