APPENDIX F. FISHES. 219 



and show traces of a bifurcation of the third degree upon their ex- 

 tremity. 



D XL 10 ; A III. 9 ; O 2. 1. 8. -1. 1. 2 ; V I. 5 ; P 14. 



The scales are proportionally large, higher than long, subtruncated 

 anteriorly, and rounded posteriorly with minute denticulations. Scales 

 irregularly disposed, exist on the base of the caudal. The largest scales 

 are seen on the middle of the flanks, and the smallest upon the sub- 

 thoracic region. The ground-color appears to have been of a uniform 

 reddish brown. The opercular flap is deep black, margined with a 

 lighter line, the hue of which is not preserved. There are several sinu- 

 ous irregular lines upon the cheeks and opercular apparatus. 



This species has a general resemblance to Pomotis nietidus, Kirt, 

 but may easily be distinguished by prominent characters. 



One specimen was caught in Otter creek, Arkansas. 



Plate XIII, Pomotis breviceps of natural size. 



Fig. 2. A dorsal scale. 



Fig. 3. A scale from the lateral line. 



Fig. 4. A scale from the sides of the belly. 



Figs. 2-4 are enlarged twelve times. 



3. Leuciscus vigilax, B. h G.* 



Zoology, PI. XIV, figs. 1-4. 



t 



Spec. char. — Subfusiform. Dorsal fin longer than high. Sixteen 

 rows of scales across the line of greatest depth, and eight on the pedun- 

 cle of the tail. Thirty-eight to forty scales in the lateral line, which 

 runs through the middle of the sides, slightly bent downwards on the 

 abdomen. 



Syn. — Ceratichthys vigilax, B. & G. Proc. Acad. Nat. Sc. Philad. 

 VI, 1853, 391. 



Description. — Body subfusiform, compressed. The head forms one- 

 fifth of the entire length from the snout to the tip of the caudal fin ; 

 it is contained three times in the length of the body, the caudal fin 

 being about one-fifth of the entire length. The head itself has the 

 shape of a truncated cone. The eyes are subelliptical ; their longitudi- 



* Note. — Owing to the immature state of the specimens, we have preferred 

 returning this species to the genus Leuciscus. Although having a strong resem- 

 blance to Ceratichthys, as also to Pimephales, in the bluntness of the snout, the 

 inferior position of the mouth, and other characters, yet the specimen is almost 

 too small to allow a final determination as to its generic character. 



