16 
U. 8. P. R. R. EXP. AND SURVEYS — ZOOLOGY-GENERAL REPORT. 
4. CALLIURUS LONGULUS, Grd. 
Plate V, Figs. 5—8, and Plate VI, Figs. 5—8. 
Spec. Ciiab. —Mouth moderate, gape oblique upwards. Posterior extremity of maxillary extending to a vertical line 
intersecting the pupil. Eyes moderate. Insertion of ventrals situated opposite the inferior edge of the base of the 
pectorals and posteriorly to the origin of the dorsal, their tips extending to the vent. Scales moderate. Reddish brown 
above ; greyish beneath. Soft portion of dorsal and anal fins provided with a black patch. 
Syn. — Pomotis longulus, B. & G. Proc. Acad. Nat. Sci. Philad. VI, 1853, 391 ; and, in Marcy’s Expl. Red River, La., 
1853, 245, pi. xii. 
Bryttus longulus, B. & G., Proc. Acad. Nat. Sci. Philad. VII, 1854, 25. 
Successively placed by us in the genera Pomotis and Bryttus , this species is now referred to 
Calliurus, tbe genus to which it properly belongs. 
It is not without a certain general resemblance with C. formosus, and the inquiries respecting 
C. punctulatus are applicable to it as well as to C. formosus. One point in regard to C. punctu- 
latus strikes us as desirable to be known in order to settle this question : the black patch upon 
the posterior portion of the dorsal and anal fins, and about which Rafinesque is silent. Is the 
inference to be drawn that, since Rafinesque omits to inform us on that point, the black patches 
alluded to do not exist ? 
The traits by which this species is to be distinguished from C. formosus consist chiefly in the 
structure of the mouth, which is not so deeply cleft as in the latter ; hence the posterior 
extremity of the maxillary does not extend so far back with reference to the orbit. 
The general aspect of the fish, when seen in profile, is sub-elliptical, and occasionally quite 
regularly so. The greatest depth is equal to the third of the total length, in which the head 
enters about three times and a half. The jaws are sub-equal, the lower one projecting but slightly 
beyond the upper. The posterior extremity of the maxillary reaching a vertical line drawn 
through the middle of the pupil. The tongue is smooth. The eye is rather moderate in size 
and sub-circular in shape; its horizontal diameter entering about four times and a half in the 
length of the side of the head. 
Br. YI: YI; D X, 12; A III, 9; C 4, 1, 8, 7, 1, 3; V I 5; P 14. 
The scales are deeper than long, seemingly identical with those of C. formosus, except that 
the pectinations are more strongly marked. 
The color is reddish brown above and greyish beneath. Sometimes the flanks appear as if 
streaked with light bands corresponding to the rows of scales, and owing to the periphery of 
the scale being darker than its middle. The sides of the head are variegated with sinuous light 
lines. The dorsal and anal are provided with a black patch upon the posterior portion of their 
base. 
Beferences to the figures. —Plate Y, fig. 5, represents Calliurus longulus , size of life, from the 
Rio Cibolo. Fig. 6 is a scale from the dorsal region. Fig. I is a scale from the lateral line. 
Fig. 8, a scale from the abdominal region. 
Plate YI, fig. 5, represents the same species, size of life, from the Rio Seco. Figs. 6, I, and 
8, are enlarged scales from the dorsal region, the lateral line, and the abdominal region. 
The species is more correctly illustrated on plate V than on plate YI. 
