FRB: Thecate hydroids from the shelf waters of northern Canada

Based largely on collections from the Calanus-Salaelinus expeditions, 54 species of thecate hydroids were identified from the shelf waters of northern Canada between northeastern Newfoundland and the Alaska-Yukon border. Thecates were found in material from 84 of the stations occupied by M.V. Calanus and M.V. Salvelinus,. The source report contains reference to previously unreported hydroids from arctic Canada in the collection of the Museum of Natural Sciences - these specimens are not included in this datasets. Specimens from these two collections were identified by Dale R. Calder who at that time worked at the Museum of Natural Sciences, National Museums of Canada, Ottawa, Ontario. or - are included but flagged with collectionCode of CMN and institutionCode.