218 U. S. P. E. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



CARPIODPJS, Rafin. 



GEN. CHAR. Mouth rather small, inferior, protractile, tubuliform when protracted, surrounded by narrow lips, transversly 

 folded. Lower jaw shorter than the upper. 



SYN. Carpiodes, RAFIN. Ichthyol. Ohiens., 1820, 56. AGASS. in Amer. Journ. of Sc. and Arts, second series, XIX, 1855, 74. 



The above are the only characters which we have so far been able to detect as properly 

 belonging to Carpiodes, leaving aside the pharyngeal bones and the teeth. In Bubaliclithys 

 &quot;the mouth opens obliquely downwards and forwards, the lower jaw being nearly as long as the 

 upper. The lips are small and granulated.&quot; In Ictidbus &quot;the mouth opens directly forwards, 

 and is large and round. The lips are small, smooth and thin.&quot; Whatever else has been 

 said concerning generic differences between these three genera we have not found them to apply 

 strictly. But, as already stated, we lack materials, for the present, and must defer to a future 

 opportunity the revision of this curious group of fishes. 



CABPIODES DAMALIS, Grd. 

 PLATE XL VIII, FIGS. 14. 



SPEC. CHAR. Head constituting the fifth part of the total length. Eye sub-circular, its diameter being contained four times 

 and a half in the length of the side of the head. Angle of the mouth reaching a vertical line drawn in advance of the pupil. 

 Insertion of ventral fins opposite the seventh ray of the dorsal. Caudal posteriorly concave. Dorsal fin superiorly concave. 

 Lower fins moderately developed. Scales deeper than long, grooved on all sides. Reddish brown above ; silvery beneath. 



STN. Carpiodes damalis, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 170. 



I have before me a specimen of this species measuring seven inches and three-quarters in 

 total length. The greatest depth of the body is contained about three times and a half in that 

 length, whilst the head constitutes the fifth part of it. The dorsal is much longer than high 

 anteriorly ; its anterior margin is nearer the end of the snout than the insertion of the caudal 

 fin, which is posteriorly concave. The origin of the ventrals is situated opposite the fifth 

 developed ray of the dorsal, the seventh in the series. The pectorals are small. The branchi- 

 ostegals are three on either side. 



Br. Ill : III ; D 2T ; A 10 ; C 4, 1, 8, 8, 1, 3 ; V 10 ; P 16. 



The anterior two rays, in both the dorsal and anal fins, are rudimentary, as also the exterior 

 one in the ventrals. 



The eye is sub-circular, its diameter being contained four times and a half in the length of 

 the side of the head. The snout is sub-conical. A line drawn perpendicularly to the angle of 

 the mouth would pass in advance of the pupil. The sub-opercle is largely developed, and 

 contrasts greatly with its reduced size in 0. (/.) tumidus, figured in the report of the United 

 States and Mexican Boundary Survey. 



The scales are very large ; thirteen lateral rows may be counted from the anterior margin of 

 the dorsal to the insertion of the ventrals. They are somewhat higher than long, with 

 radiating furrows all around, more numerous upon the anterior section than elsewhere. The 

 lateral line undergoes a slight fall upon the thorax, then runs straightway to the base of the 

 caudal along the eighth row of scales under the anterior margin of the dorsal. 



References to the figures. Plate XL VIII, fig. 1, represents, size of life, Carpiodes damalis. 

 Fig. 2, a scale from the dorsal region. Fig. 3, a scale from the lateral line. Fig. 4, a scale 

 from the abdominal region. 



