Bj rklund BG. 2009. Freshwater rotifers from Hordaland western Norway with a u survey of freshwater rotifers previously found in Norway. Fauna Norvegica29: 11-54. A total of 156 species (or subspecies) o rotifers, mostly non-planktonic, have been identified from freshwater or slightly brackish-water localities in the county of Hordaland; 83 are new to Norway and 24 others are new to the county. One hundred of the species were collected from the two valleys of Eksingedalen and Teigdalen in spring and summer 1967. Samples were taken on the shallow shores of lake-like parts of the rivers, and in pools, tarns and small lakes. Forty more or less euryhaline fresh-water rotifers were also collected during studies of slightly brackish-water localities around Bergen in 1963-1969. A number of freshwater rotifers were collected at several localities in and around Bergen in 1968-1970, and on the western part of Hardangervidda. Of those so far identified ,23 are new to Norway and 8 more are new to the county. They are therefore included in the species list. A few additional ones are referred to in the taxonomical notes. All the species are listed with localities and habitat categories, or, in the case of the last-mentioned ones, just the district where they were collected. The paper includes notes, measurements and ,in most cases, figures regarding 44 little known, variable or taxonomically problematical species, especially in the genera Cephalodella and Trichocerca. Comments are given on the distribution , abundance and diversity of the species. The paper presents asurvey of previous investigations on rotifers in Norway, listing 200 previously recorded freshwater (a few euryhaline) rotifers, giving other names, the authors who recorded the finds and, in most cases, the counties where the species were collected.