In the negro-chub, Exoglossum maxillingua of the Pennsylvanian district, the rami of the lower jaw are united for their whole length, looking like a projecting tongue.
Fig. 128.—Head of Day-chub, Exoglossum maxillingua (Le Sueur). Shenandoah River.
The fallfish, Semotilus corporalis, is the largest chub of the Eastern rivers, 18 inches long, living in swift, clear rivers. It is a soft fish, and according to Thoreau "it tastes like brown paper salted" when it is cooked. Close to this is the horned dace, Semotilus atromaculatus, and the horny head, Hybopsis kentuckiensis, both among the most widely distributed of our river fishes. These are all allied to the gudgeon (Gobio gobio), a common boys' fish of the rivers of Europe, and much sought by anglers who can get nothing better. The bream, Abramis, represented by numerous species in Europe, has a deep compressed body and a very long anal fin. It is also well represented in America, the golden shiner, common in Eastern and Southern streams, being Abramis chrysoleucus. The bleak of Europe (Alburnus alburnus) is a "shiner" close to some of our species of Notropis, while the minnow of Europe, Phoxinus phoxinus, resembles our gorgeously colored Chrosomus erythrogaster. Other European forms are the roach (Rutilus rutilus), the chub (Leuciscus cephalus), the dace (Leuciscus leuciscus), the id (Idus idus), the redeye (Scardinius erythropthalmus), and the tench (Tinca tinca). The tench is the largest of the European species, and its virtues with those of its more or less insignificant allies are set forth in the pages of Izaak Walton. All of these receive more attention from anglers in England than their relatives receive in America. All the American Cyprinidæ are ranked as "boys' fish," and those who seek the trout or black bass or even the perch or crappie will not notice them. Thoreau speaks of the boy who treasures the yellow perch as a real fish: "So many unquestionable fish he counts, then so many chubs which he counts, then throws away."
Fig. 129.—Horned Dace, Semotilus atromaculatus (Mitchill). Aux Plaines River, Ill. Family Cyprinidæ.
Fig. 130.—Shiner, Abramis chrysoleucus (Mitchill). Hackensack River, N. J.
Fig. 131.—The Squawfish, Ptychocheilus grandis Agassiz. (Photograph by Cloudsley Rutter.)