16 r. S. p. R. R. EXP. AXD SURVEYS— ZOOLOGY GENERAL REPORT. 



4. CALLIURUS LONGULUS, Grd. 



Plate V, Figs. 5—8, and Plate VI, Figs. 5—8. 



Spec. Ciiab.— Mouth moderate, gapo 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 tho 

 pectorals and posteriorly to the origin of tho 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. 



STU.—Pomotin lotiyulus, B. & G. Proc. Acad. Nat. Sci. Philad. VI, 1853, 391 ; and, in Mabcy's Expl. Red River, La., 



1853, 245, pi. xii. 

 Brytlm Imgidwi, B. & G., Proc Acad. Nat. Sci. Philad. VH, 1854, 25. 



Successively placed by us in the genera Pomotis and Bryttus, this species is now referred to 

 Calliurus, the genus to which it properly belongs. 



It is not without a certain general resemblance with C. formosus, and the inquiries respecting 

 C. punctulalus are applicable to it as well as to C. formosus. One point in regard to C. puncfu- 

 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 Eafinesque 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 tlie 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. VI: VI; U X, 12; A III, 9; C 4, 1, 8, 7, 1,3; VI 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. 



References to the figures. — Plate V, fig. 5, represents CalUurtis longulus, size of life, from the 

 Eio Cibolo. Fig. 6 is a scale from tha dorsal region. Fig. 7 is a scale from the lateral line. 

 Fig. 8, a scale from tlie abdominal region. 



Plate VI, fig. 5, represents the same species, size of life, from the Rio Seco. Figs. 6, 7, 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 VI. 



