314 Bulletin 47, United States National Museum. 



the longer; maxillary reaching about line of orbit; mouth forming more 

 than a semicircle. Fins long, the ventrals reaching anal. Color, dark iron 

 gray above, sometimes spotted ; a darker band of same along sides above 

 lateral line, extending from end of snout to middle of caudal where it 

 is most conspicuous; males with the belly yellow or orange. Tributaries 

 of the Gila River, not rare in mountain brooks, (xpvaof , gold ; yaarfip, 

 belly.) 



Agosia chrysogatter, GIBARD, Proc. Ac. Nat. Sci. Phila., 1856, 187, and U. S. & Mex. Bound. 



SUIT.. Zool., 49, plate xxvni, figs. 5 to 8, 1859, Rio Santa Cruz, Sonora. (Coll. Clark.) 



JORDAN & GILBERT, Synopsis, 209, 1883. 

 Agosia metallica, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 187, and U. S. & Mex. Bound. Surv., 



Zool., 49, plate xxvni, figs. 1 to 4, 1859, Rio San Pedro, Arizona. (Coll. Clark.) JOR- 

 DAN & GILBERT, Synopsis, 209, 1885. 

 Hyborhynchtts stcZerius,* (lapsus for Hybognathus), COPE, Zool. Wheeler Surv., v, 670,^ plate xxxi, 



figs. 6, 6a, 1875, (1876), Camp Lowell, Arizona. (Type, No. 16984. Coll. Butter.) 

 Zophendum siderium, JORDAN & GILBERT, Synopsis, 155, 1883. 



130. HYBOPSIS, Agassiz. 



(HORNY-HEADS.) 



Hybopsis, AGASSIZ, Amer. Journ. Sci. Arts, 1854, 358, (gracili8=amblops). 



Noc&mis, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 190, (nebrascensis = kentuckiensis). 



Ceratichthys, Baird MS., GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 212, (bigtittatus = kentuckienris). 



Erinemus, JORDAN, Man. Vert., Ed. r, 279, 1876, (hyalinus = amblops). 



Erimystax, JORDAN, Geol. Surv. Ohio, iv, Zool., 858, 1882, (dissimilis). 



Yuriria, JORDAN & EVERMANN, new subgenus, 



Body robust, or variously elongate. Mouth terminal or inferior, with 

 lips thin or somewhat fleshy, a conspicuous barbel always present and 

 terminal on the maxillary ; a second barbel sometimes present on each side ; 

 premaxillaries protractile. Teeth 4-4, or 1, 4-4, 1, or ; hooked, the grind- 

 ing surface narrow or obsolete. Scales usually rather large, 35 to 58 in 

 lateral line ; lateral line continuous. Dorsal fin inserted over, in front of, 

 or slightly behind ventrals ; anal basis short. Males usually with nup- 

 tial tubercles, and sometimes flushed with red. A large and varied group, 

 closely allied to Notropis, from which it differs chiefly in the presence of 

 the small maxillary barbel. We here divide it into 4 subgenera, but a 

 greater number of subordinate groups could be recognized. The group 

 shows a range of variation as wide as that in Notropis, though with a 

 smaller number of species. (vf3bc, gibbous ; b^ig , face.) 



a. Species of moderate or small size, the mouth inferior, horizontal ; preorbital broad, silvery ; 



sexes similar, the male sometimes tuberculate or with the fins rosy. 

 ERIMYSTAX, (e'pi, an intensive particle ; fnfcra, barbel or moustache) : 

 6. Teeth one-rowed, 4-4 ; lips thickish ; body long and low, with the aspect of Gobio or 



Phenacobius. 

 c. Teeth without grinding surface ; sides not marked by a series of dark blotches con- 



nected by a lateral band ; eye moderate, 3% to 5% in head. 

 d. Scales rather large, 35 to 44 in the lateral line ; barbel very long, sometimes 

 duplicated ; dorsal fin without black blotch on its upper posterior por- 

 tion ; snout projecting ; body slender ; fins high. 



* In the type of H. siderius the barbel is plainly evident, a fact which Mr. Barton A. Bean has 

 recently kindly verified for us. 



