Notwithstanding the mud bottoms, the water in this kind of stream in the Big Blue Basin remains clearer than that of the Big Blue and Little Blue rivers. Heavy algal blooms were noted in the Black Vermillion River and Mill Creek, Washington County, in 1957 and 1958. Temperatures at Stations 45-M and 46-M on Mill Creek, Washington County, averaged 85.5 deg. F. on July 31, 1957. Chemical characteristics of a water-sample from Station 35-M, Black Vermillion River, are in Table 1. GRAVEL-BOTTOMED STREAMS.--Most streams of this kind are tributary to the Big Blue River; however, streams entering Black Vermillion River from the south are also of this type (Plate 12, Fig. 2). The streams are "characteristically a series of large pools (to 100 feet in length and more than two feet in depth) connected by short riffles and smaller pools" (Minckley and Cross, in press). The average gradients are high: Carnahan Creek, 33 feet per mile; Mill Creek, Riley County, 21 feet; Clear Creek, 16 feet per mile. Stream-flow is usually less than five cubic feet per second. In summer, these streams may become intermittent, but springs and subsurface percolation maintain pool-levels (Minckley and Cross, _loc. cit._). The average temperatures of these small streams (79.5 deg. to 81.0 deg. F. in July and August, 1957) were lower than temperatures in stream-types previously described. Turbidities were usually less than 25 p.p.m. The chemical properties of water-samples from two of these streams (Stations 11-G and 18-G) are listed in Table 1. PREVIOUS RECORDS OF FISHES The earliest records of fishes from the Big Blue River Basin are those of Cragin (1885) and Graham (1885) in independently published lists of the fishes of Kansas. Meek (1895) recorded fishes collected in 1891 "from both branches of the Blue River, a few miles west of Crete, Nebraska." Evermann and Cox (1896) reported five collections from the Nebraskan part of the basin. Their collections were made in October, 1892, and August, 1893, and the stations were: in 1892, Big Blue River at Crete; in 1893, Big Blue River at Seward, Lincoln Creek at Seward and York, and Beaver Creek at York. Canfield and Wiebe (1931) obtained fish from 18 localities in Nebraska in July, 1930; however, their major concern was determination of water quality. Their stations were: Big Blue River at Stromsburg, Polk Co.; Surprise and Ulysses, Butler Co.; Staplehurst, Seward, and Milford, Seward Co.; Crete and Wilber, Saline Co.; Beatrice, Blue Springs, and Barnston, Gage Co.; Little Blue River at Fairbury, Jefferson Co.; Hebron, Thayer Co.; Sandy Creek at Alexandria, Thayer Co.; West Fork of Big Blue River at Stockham, Hamilton Co.; McCool Junction, York Co.; Beaver Crossing, Seward Co.; and Beaver Creek at York, York Co.