222 APPENDIX F. FISHES. 



Fig. 8. Abdominal scale. 



Figs. 6-8 are enlarged twelve times. 



5. Leuciscus lutrensis, B. & G-. 



Zoology, PI. XIV, figs. 9-12. 



Spec. char. — Subfusiform, compressed. Insertion of ventrals in ad- 

 vance of dorsal. Twelve rows of scales across the lin9 of greatest 

 depth ; six rows on the tail. About thirty-six in the lateral line, which 

 is bent downwards on the abdomen and slightly broken in advance of 

 the anal fin. Dorsal and anal fins well developed. 



Syn. — Leuciscus lutrensis, B. & G-. Proc. Acad. Nat. Sc. Phiiad. VI, 

 1853, 391. 



Description. — The body is much compressed and subfusiform in gen- 

 eral appearance, somewhat tapering from the posterior margin of the 

 dorsal and anal fins to the caudal, the base of which is broader than the 

 peduncle of the tail. The greatest depth is equal to the length of the 

 sides of the head, which is contained three times and a half in the total 

 length, the caudal fin included. The greatest thickness is nearly half 

 of the depth. In general aspect it resembles Leuciscus Jcentuckiensis 

 of Kirtland. The. eyes are of medium size, subcircular ; their diameter 

 contained four times in the length of the sides of the head. The nos- 

 trils, situated towards the upper surface of the head, are nearer to the 

 eyes than to the tip of the snout. The posterior extremity of the max- 

 illary does not reach the vertical of the anterior rim of the orbit. 



The upper and posterior margins of the opercular constitute a uniform 

 curve, whilst the anterior and inferior margins are straight, forming a 

 rather acute angle. The suboperculars and interoperculars are compara- 

 tively small. 



The anterior margin of the dorsal fin is situated on the middle of the 

 distance between the snout and the base of the caudal ; the fin itself is 

 quadrangular, higher than long, and composed of eight rays, the last 

 double, and the anterior rudimentary in close contact with the next. 

 The anal is shaped somewhat like the dorsal ; it has nine perfect rays 

 and an anterior rudimentary one. The caudal is deeply forked with 

 acute angles, and shorter than the head. It is composed of nineteen 

 well developed rays, and several rudimentary ones, above and below. 

 The ventrals are posteriorly rounded, (a character not expressed in the 

 figure,) composed of eight rays, and when bent backwards their tips 

 reach the anus, which is situated immediately in advance of the anal 

 fin. The pectorals are elongated, rather slender, rounded, and their tip 



