=Semotilus atromaculatus= (Mitchill), creek chub: Evermann and Cox (1896:399); and Jennings (1942:364) as _Semotilus atromaculatus atromaculatus_ (Mitchill). Stations 5-G, 7-G, 10-G, 11-G, 12-G, 13-G, 16-G, 17-G, 18-G, 23-G, 24-G, 27-G, 28-G, 29-G, 31-G, 32-G, 33-M, 34-M, 36-M, 37-M, 40-M, 46-M, 47-M, 48-M, 49-M, 50-S, 53-S, 54-G, 55-M, 56-S, 57-M, 58-G, and 59-G. Creek chubs were found in all habitats in the Big Blue River Basin, but were abundant only in the headwaters of muddy streams and in clear upland creeks. =Chrosomus erythrogaster= (Rafinesque), southern redbelly dace: Jennings (1942:365). Stations 11-G, 12-G, 13-G, 16-G, 27-G, 29-G, and 53-S. This colorful species occupied the headwaters of the clear, spring-fed creeks where it was abundant. Only one specimen was taken in muddy or sandy habitat (at the mouth of a small creek at Station 53-S), where it may have been washed by floods just prior to my collecting. =Hybopsis storeriana= (Kirtland), silver chub. Station 3-S. One specimen of _H. storeriana_ (KU 3810) was seined in swift water near a sandbar on April 6, 1957, and another was taken at the same locality on April 26, 1958. =Hybopsis aestivalis= (Girard), speckled chub: Meek (1895:137); and Evermann and Cox (1896:409), both as _Hybopsis hyostomus_ Gilbert. Stations 3-S, 4-S, 14-S, 25-S, 38-S, 39-S, 50-S, and 56-S. This species was restricted to wide, swift parts of the Big Blue and Little Blue rivers, and was found over clean, sometimes shifting, sand bottoms. On May 29, 1958, three males in breeding condition were collected and on June 16, 1958, a large series of both male and female _H. aestivalis_, all with well-developed gonads, was collected. The water temperature was 77.0 deg.F. Hubbs and Ortenburger (1929:25-26) reported that _Extrarius tetranemus_ (Gilbert) (= _Hybopsis aestivalis tetranemus_) spawns in summer especially in early July. Cross (1950:135) reported a single pair of _H. a. tetranemus_ that he considered in breeding condition on June 9, 1948. Breukelman (1940:380) recorded speckled chubs in the Kansas River Basin as _Extrarius_ (= _Hybopsis_) _aestivalis_: _sesquialis_ x _tetranemus_; however, the name _sesquialis_ is a _nomen nudum_, and the status of this species in the Kansas River Basin is yet to be elucidated. =Phenacobius mirabilis= (Girard), plains suckermouth minnow: Meek (1895:136); and Evermann and Cox (1896:408). Stations 2-S, 3-S, 4-S, 5-G, 6-S, 7-G, 8-S, 9-G, 11-G, 16-G, 18-G, 25-S, 26-G, 27-G, 35-M, 38-S, 39-S, 40-M, 42-S, 47-M, 50-S, 52-S, 53-S, 54-G, and 56-S. _Phenacobius mirabilis_ was widespread in the basin, occurring most frequently on riffles over bottoms of clean sand or gravel. Young-of-the-year were usually taken in backwaters. =Notropis percobromus= (Cope), plains shiner. Stations 3-S and 4-S. The plains shiner occurred only in the lower part of the main stream of the Big Blue River. =Notropis rubellus= (Agassiz), rosyface shiner. Station 5-G.