The redfin shiner flourished in all the streams surveyed except the Arkansas and Walnut Rivers. N. umbratilis has been found in upland tributaries of the Walnut River, some of which originate in terrain similar to that in which Elk River, Big Caney River, and Grouse Creek originate. (Collection C-26-51 by Cross on Durechon Creek, October 7, 1951.) This suggests downstream reduction in relative numbers of this species, a tendency which also seemed to exist on both Big Caney River and Grouse Creek. N. umbratilis was the most abundant species in Big Caney River except at the lowermost stations where it was surpassed in relative abundance by N. lutrensis and Gambusia affinis.
N. umbratilis was a pool-dweller, becoming more concentrated in the deeper pools as summer advanced. In May and early June, large concentrations of adult N. umbratilis were common in the shallow ends of pools together with N. rubellus, N. boops, Pimephales notatus, and Pimephales tenellus. By July and August, only young of the year were taken in shallow water, and adults were scarcely in evidence.
Notropis volucellus (Cope): Stations G-5, G-8, C-3, C-5, C-7, C-8, C-9, C-10, M-1, E-4, E-5.
The mimic shiner was a minor element in the fauna, 2.02 per cent at station C-5 being the largest percentage taken. In the Big Caney River system N. volucellus was taken only in the main stream. In the Grouse Creek drainage it was found at two stations in the upper part of the watershed, where water is clearer, gradient greater, and pools well-shaded and cool.
In the Elk River the mimic shiner was taken only in the upper part of the main stream. The dominant shiner in situations where N. volucellus was taken was, in all cases, N. umbratilis. Elliott (1947) found N. volucellus in Spring Creek, a tributary of Fall River. Farther north in the Flint Hills region, N. volucellus was reported by Cross (1954a:310).
Notemigonus crysoleucas (Mitchell): Station W-5.
This isolated record for the golden shiner consisted of nine specimens collected on June 6 in Timber Creek, a tributary of the Walnut River. Most of the creek was dry. N. crysoleucas was taken in one pool with dimensions of 8 feet by 4 feet with an average depth of 4 inches. This creek is sluggish and silt-laden, even under conditions of favorable precipitation. Hubbs and Ortenburger (1929b:89) observed that the golden shiner prefers sluggish water. Hall (1952:58) took the golden shiner only in the lowland tributaries west of Grand River and not east of the river in upland tributaries.
Phenacobius mirabilis Girard: Stations W-3, C-3.
In no case was the suckermouth minnow common; it never comprised more than 1 per cent of the fish population.