On 19 June, 1959, I saw many buffalo that seemed to be feeding as they moved slowly upstream along the bottom of a riffle. The two species, often side by side, were readily distinguishable underwater. Small-mouthed buffalo appeared to be paler (slate gray) and more compressed than the darker black buffalo. To test the reliability of underwater identifications, I identified all individuals prior to collection with a gig. Correct identification was made of all fish collected on 19 June. The smallest individual obtained in this manner was 18.5 inches T. L. On 26 August, 1959, 16 small-mouthed buffalo were captured and many more were seen while the shocker was in use in the same riffle for one hour and ten minutes. One small-mouthed buffalo was caught while the shocker was being used in the pool below that riffle for one hour and fifty minutes. No black buffalo were taken on 26 August. Spawning by buffalo was not observed but probably occurred in spring; all mature fish in my earliest collections (mid-June of each year) were spent. Small-mouthed buffalo reach maturity at approximately 14 inches T. L. #Carpiodes carpio carpio# (Rafinesque) River Carpsucker River carpsucker were abundant throughout the study at all stations. Adults were taken most frequently in quiet water, but depth and bottom-type varied. The greatest concentrations occurred in mouths of creeks during times of high water; occasionally, large numbers were taken in a shallow backwater near the head of a riffle at the middle Neosho station. River carpsucker feed on the bottom but seem partly pelagic in habit. They were taken readily by means of the shocker and gill nets at all depths. The population of _C. carpio_ in the Neosho River probably was depleted by drought, although many individuals survived in the larger pools. When stream-flow was restored, carpsucker probably moved rapidly upstream but had a scattered distribution in 1957. Trautman (1957:239) states that in the Scioto River, Ohio, river carpsucker moved upstream in May and downstream in late August and early September. Numbers found at the middle and lower Neosho stations suggest similar movements in the Neosho River in 1957. In midsummer they were common at the middle station but rare at the lower station; however, they became abundant at the lower station in November. The abundance in late fall at the lower Neosho station might have resulted either from downstream migration or from continued upstream movement into thinly populated areas. No indication of seasonal movement was found in 1958 or 1959. River carpsucker reach maturity at approximately 11 inches T. L., and spawning occurs in May or June. A ripe male was taken from a gravel-bottomed riffle, three feet deep, at the middle station on the Neosho station on 10 June 1959.