256 



U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



The shortness of the lower jaw, which exposes the anterior extremity of the tongue, is a 

 feature exclusively peculiar to this genus. That the structure just alluded to is really of a 

 generical value, is evinced by the fact that two species are now known to possess it. The general 

 aspect, as well as the structure of the scale , are similar to those of Nocomis. 



EXOGLOSSUM MIRABILE, Grd. 



Plate LVI, Figs. 5—8. 



Spec. Char. — Head sub-conical, blunt, and constituting the sixth of the total length. Mouth small ; posterior extremity of 

 maxillar bone even with a vertical linedravpn across the nostrils. Eye sub-circular; its diameter entering four times in the length 

 of the side of the head. Anterior margin of dorsal much nearer the extremity of the snout than the base of the caudal. Inser- 

 tion of ventrals placed somewhat posteriorly to the anterior margin of the dorsal, their tip nearly reaching the vent. Reddish 

 brown above ; middle of flank with a silvery band ; beneath light reddish. 



Stn. — Exoglossum mirabile, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 191. 



A very characteristic species, very slender and fusiform, and distinguished from E. maxillingua 

 by a smaller head, smaller mouth, the position a little more backwards of the ventrals, and 

 larger scales. The latter are longer than deep, except in the lateral line, anteriorly sub-trun- 

 cated, posteriorly rounded, with radiating furrows upon the posterior section only ; the lateral 

 line is straight and median. The dorsal is higher, and the anal deeper, than broad upon their 

 base. The caudal fin enters nearly five times and a half in the total length. 

 D 2, 8 + 1 ; A 2, 7 + 1 ; C 12, 1, 9, 8, 1, 10 ; V 8 ; P 15. 



The color is reddish brown above, light reddish beneath, with a silvery band along the middle 

 of the flanks from head to tail. A black spot may be observed upon the insertion of the 

 caudal fin. 



lieferencesto the fgures. — Plate LVI, fig. 5, represents Exoglossum mirabile, size of life. Fig. 

 6 is a scale from the dorsal region. Fig. 7, a scale from the lateral line. Fig. 8, a scale from 

 the abdominal region. 



List of specimens. 



CLIOLA, Girard. 



Gen. Char. — Body slender and sub-fusiform in profile, compressed ; snout rSunded ; mouth small and terminal, with both 

 jaws equal. There is a rather wide isthmus. Tlio eyes are well developed also. The dorsal fin is about as long as high, or 

 longer than high. The caudal fin is furcated ; the insertion of the ventrals, opposite the anterior margin of the dorsal. The 

 scales being large, and the lateral line following the middle of the flanks. Tlic pharyngeal bones are of moderate strength ; the 

 inferior branch is rather slender, and nearly straight when viewed in front; from the insertion of the teeth, they gradually 

 expand to the entire convexity, which is gentle and gradual. The teeth themselves are of the raptatorial kind, of the hooked 

 type, without grinding surface, compressed, curved, and disposed upon one single row of four : 4 — 4. 



Stn CHola, Grd. in Proc. Acad. Nat. Sc. Philad. VlII, 1856, 192. 



The species of this genus have the external aspect of Diorida, but differ from the latter by the 

 pharyngeal teeth, which are curved and without grinding surface. 



