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. [Illustration: 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." [Illustration: FIG. 129.—Horned Dace, _Semotilus atromaculatus_ (Mitchill). Aux Plaines River, Ill. Family _Cyprinidæ_. ] [Illustration: FIG. 130.—Shiner, _Abramis chrysoleucus_ (Mitchill). Hackensack River, N. J. ] [Illustration: FIG. 131.—The Squawfish, _Ptychocheilus grandis_ Agassiz. (Photograph by Cloudsley Rutter.) ] =Chubs of the Pacific Slope.=—In the Western waters are numerous genera, some of the species reaching a large size. The species of squawfish (_Ptychocheilus lucius_ in the Colorado, _Ptychocheilus grandis_ in the Sacramento, and _Ptychocheilus oregonensis_ in the Columbia) reach a length of 4 or 5 feet or even more. These fishes are long and slender, with large toothless mouths and the aspect of a pike.