Specimens of _H. g. gulonella_ collected in the Arkansas River at Pueblo and Florence, Colorado, on September 7, 1959, include some tuberculate males, although most females are spent. On August 8, 1957, a series of flathead chubs that includes tuberculate males was collected in the Redwater River, Montana. In the Pecos River on August 25, 1958, spawning seemingly had been completed, although a few males still bore tubercles. TABLE 1. ORGANISMS FOUND IN STOMACHS OF HYBOPSIS GRACILIS FROM VARIOUS LOCATIONS, EXPRESSED AS PERCENTAGE OF TOTAL VOLUME. A: S. Saskatchewan R., Clarkboro Ferry, Sask. B: Milk R., Alberta C: Missouri R., S. D. D: Missouri R., Neb. E: Arkansas R., Fremont Co., Colo. F: Arkansas R., Pueblo Co., Colo. G: Pecos R., San Miguel Co., N. M. ==============================+=====+=====+=====+=====+=====+=====+===== | A | B | C | D | E | F | G ------------------------------+-----+-----+-----+-----+-----+-----+----- No. specimens examined | 1 | 7 | 6 | 10 | 10 | 10 | 10 | | | | | | | No. specimens containing food | 1 | 6 | 1 | 2 | 1 | 3 | 7 ------------------------------+-----+-----+-----+-----+-----+-----+----- KIND OF ORGANISM | | | | | | | | | | | | | | Aphasmidia |10.0 |00.7 | |03.0 | | | Arthropoda | | | | | | | Araneae | | | | | | | Argiopidae | | | | |04.0 | | Theridiidae | | | | |04.0 | | Insecta | | | | | | | Ephemeroptera (nymph) | | | | | | | Baetidae | |05.0 | | | | | Heptagenidae | |08.0 | | | | | Hemiptera | | | | | | | Corixidae |35.0 |00.3 | | | | | Hymenoptera | | | | | | | Formicidae | |21.0 | | | | |60.0 Coleoptera | | | | | | | Staphylinidae | |01.7 |07.0 | | | | Scolytidae | |13.3 |70.0 | | | | Tenebrionidae | |05.7 | | |70.0 | | Carabidae | |05.7 | | | |01.0 | Curculionidae | |01.0 | | | | | Coccinellidae | | | | | | |09.0 Trichoptera (case) | |01.7 | | | | | Diptera | | | | | | |