184 CTPKIKID^. 



Hyborliynchus, Girard, U. S. ^- Prac. R. JR. E.iyed. Fish. p. 230 (not 



Af/fissiz). 

 Ilybognatlms, Agassiz, Amcr. Joian. Sc. ^- Arts, 1855, xix. p. 22:). 



Scales of moderate or small size ; lateral line present, running 

 along the middle of the tail. Dorsal fin short, -ndthout spinous ray, 

 commencing nearlj' opposite the ventrals ; anal fin short. Mouth 

 anterior, or subanterior, narrow; intermaxillaries protractile ; lower 

 jaw with a rather sharp edge, the labial fold being developed on the 

 side only. Barbels none. Gill-rakers short; pseudobranchiffi. The 

 attachment of the gill-membrane to the isthmus takes place opposite 

 to the angle of the praeoperculum. Pharyngeal teeth compressed, 

 4 — 4, or 4 . 1 — 1 . 4. Intestinal tract with numerous convolutions. 



United States. 



1. Hybognathus nuchalis. 



Agassiz, I. c. p. 224. 



D. 11. A. 9. V. 8. L. lat. 38. L. transv. 5/6. 

 The height of the body is a little more than the length of the 

 head, which is contained four times and one-thii'd in the total (with- 

 out caudal). Hind margin of the eye nearer to the end of the 

 opercle than to that of the snout ; snout scarcely longer than the 

 eye, which is one-fourth of the length of the head. The dorsal 

 begins slightly in advance of the ventrals, somewhat nearer to the 

 end of the snout than to the root of the caiulal. There are four 

 longitudinal series of scales between the lateral line and root of the 



and U. S. ^- Pac. R. R. Exped. Fish. p. 235, pi. 53. figs. 5-8.— Missouri ; 

 Arkansas. 



5. ITybngnatluis evansi, Girard. II. cc. — Nebraska, Platte River. 



6. Ceratichthys -vigilax, Baird ic Girard, Proc. Ac. Kaf. Sc. PJiilad. 1853, 



p. 391 ; Leuciscus vigilax, Baird c^- Girard, in Marcy. E.\plor. Red River, 

 1853, p. 248, pi. 24. figs. 1-4 ; C'liola vigilax, Girard. Proc. Ac. Kaf. Sc. 

 PhiJad. 1856, p. I'.t2; and U. S. df" Pac. R. R. Expcd. Fifh. p. 267.— 

 Eed River ; Arkansas. 



7. Cliola velox, Girard, Proc. Ac. Xaf. Sc. Philad. 1856, p. 192, and V. S. 



if Pac. R. R. E.xped. Fish. p. 258.— Texas. • 



8. vivax, Girard. 11. cc. — Texas. 



9. Dionda episcopa, Girard, Proc. Ac. Naf. Sc. Philad. 1856, p. 177 ; or U. 



S. # Pac. R. R. Eapcd. Fish. p. 2:^7.— Eio Pecos. 



10. papalis, Girard, I. c. 1°, p. 178 ; or /. c. 2°, p. 228. — Delaware Creek 



(Rio Pecos). 



11. plumbea, Girard, I. c. 1°, and I. c. 2°, pi. 52. figs. 21-25. — Canadian 



River. 



12. • spadicea, Girard, I. c. 1°, and /. c. 2*^, p. 229, pi. 52. figs. 26-30. — 



Fort Sniitli, Arkansas. 



13. grisea. Girard. I.e. 2°, p. 230, pi. 52. figs. 6-10. — Twenty mi'es 



west of Choctaw Agency. 



14. serena, Girard. Proc. Ac. Kaf. Sc. Philad. 1856, p. 177, and U. S. 



# Mex. Bound. 7chfht/ol. p. 42, pi. 26. figs. 9-12.— Rio Sabinal, Texas. 



15. texensis. Girard, 11. cc. fig.s. 21-24. — Rio Kueces. Texas. 



16. argentosa, Girard, I.e. 1°, p. 178, and I.e. 2°, p. 43, pi. 26. figs. 5-8. 



— Texas. 

 17. chrysitis, Girard. 11. cc. figs. \?.-\(\. — Live Oak Creek, Texas. 



18. melanops, Girard. 1. c. 1°, and /. c. 2°, p. 44, pi. 26. figs. 17-20.— 



Buena Vista, Coaluiila. 



19. coiicbi, Girard, II. cc. fig.s. 1-4. — New Leon. 



