248 CYiKiNiD.i;. 



slightly compressed, its clepth being one-fifth of the total length 

 (without caudal) ; the length of the head is one-fourth of it. Males 

 with two brown longitudinal bandS' — one from the snout, through 

 the eye, below the lateral line to the caudal, the other from above 

 the gill-opening to the caudal. The remainder of the side and belly 

 silvery (the latter reddish in the spawning-season). Females with 

 the bands indistinct. 



Pharyngeal teeth 4 or 5 — 5. 



Ohio ; Michigan. 



This diagnosis is taken from a fine example in the Liverpool 

 Museum, 2i inches long. 



Mr. Cope distinguiches another species under the name of Chro- 

 somus eos, Proc. Ac. Nat. Sc. Philad. 1861, p. 523; or Trans. Am. 

 Phil. Soc. xiii. p. 391. It is said to be distinguished by a "mouth 

 not reaching line of orbit, by the dark lines imited on caudal pe- 

 duncle ; no lateral line." Susquehannah lliver. 



3. The dorsal Jin commences hehind the root of the ventrals. JRudimental 

 cnudid rays much developed. Pharyngeal teeth in a single series 

 (Lavinia). 



57. Leuciscus exilicauda. 



La\-inia exilicauda, Baird 8,- Girard, Proc. Ac. Nat. Sc. Philad. 1854, 

 p. 1.37, and 185G, p. 184 ; U. S. Pac. R. E. Exped. Fish. p. 241, pi. 54, 

 figs. 1-4. 



compressa, Ayres, Proc. Calif. Acad. Nat. Sc. 1855, p. 21. 



D, 4-10. A. ^11. V. 11. L. lat. 60-G5. L. transv. 13/11. 



The simple caudal rays are unusually strong. The height of the 

 body is contained four times in the total length (without caudal), 

 the length of t'le head four times and two-thirds. Head compressed. 

 Snout of moderate extent, longer than the eye, the diameter of which 

 is one-fifth of the length of the head, and at least one-half of the 

 width of the intcrorbital space, which is conve: . Mouth anterior, 

 oblique, with the jaws nearly even. The maxiUary does not reach 

 the vertical from the front margin of the orbit. Pra^orbital a little 

 smaller than the postorbital, which is not twice as wide as the pre- 

 ceding suborbital. Origin of the dorsal f^u considerably nearer to the 

 root of the tail than to the end of the snout, behind the base of the 

 ventrals. Anal fin ncaiiy as long as high, caudal broad, deeply 

 forked. The length of the pectoral equals that of the ventral, and 

 is three-fifths of the distance of its root from that of the ventral. 

 Coloration uniform. 



Gill-rakers slender, lanceolate ; pharyngeal teeth 5 — 5, com- 

 pressed, not denticulated, claw-shaped. 



California. 

 a-h, c. Ten and eleven inches long. San Francisco. Presented by 

 Dr. W. 0. Ayres. 



The description of Lavinia harevqvs, Girard, Proc. Ac. Nat. Sc. 

 Philad. 1856, p. 184, or U. S. Pac. E. P. Exped. Fish. p. 242, from 

 Monterey Plains, is of a very dubious character; moreover the 



